Maya Mathur

All Publications

• Simple graphical rules for assessing selection bias in general-population and selected-sample treatment effects AMERICAN JOURNAL OF EPIDEMIOLOGY Mathur, M. B., Shpitser, I. 2024; 194 (1): 267-277

  Abstract

  When analyzing a selected sample from a general population, selection bias can arise relative to the causal average treatment effect (ATE) for the general population, and also relative to the ATE for the selected sample itself. In this paper, we provide simple graphical rules that indicate (1) whether a selected-sample analysis will be unbiased for each ATE and (2) whether adjusting for certain covariates could eliminate selection bias. The rules can easily be checked in a standard single-world intervention graph. When the treatment could affect selection, a third estimand of potential scientific interest is the "net treatment difference"-namely the net change in outcomes that would occur for the selected sample if all members of the general population were treated versus not treated, including any effects of the treatment on which individuals are in the selected sample. We provide graphical rules for this estimand as well. We decompose bias in a selected-sample analysis relative to the general-population ATE into (1) "internal bias" relative to the net treatment difference and (2) "net-external bias," a discrepancy between the net treatment difference and the general-population ATE. Each bias can be assessed unambiguously via a distinct graphical rule, providing new conceptual insight into the mechanisms by which certain causal structures produce selection bias.

  View details for DOI 10.1093/aje/kwae145

  View details for Web of Science ID 001336184600001

  View details for PubMedID 38904459

  View details for PubMedCentralID PMC11735978

• Assessing robustness to worst case publication bias using a simple subset meta-analysis BMJ-BRITISH MEDICAL JOURNAL Mathur, M. B. 2024; 384: e076851

  Abstract

  This article discusses a simple method, known as a meta-analysis of non-affirmative studies, to assess how robust a meta-analysis is to publication bias that favors affirmative studies (studies with significant P values and point estimates in the desired direction) over non-affirmative studies (studies with non-significant P values or point estimates in the undesired direction). This method is a standard meta-analysis that includes only non-affirmative studies. The resulting meta-analytical estimate corrects for worst case publication bias, a hypothetical scenario in which affirmative studies are almost infinitely more likely to be published than non-affirmative studies. If this estimate remains in the same direction as the uncorrected estimate and is of clinically meaningful size, this suggests that the meta-analysis conclusions would not be overturned by any amount of publication bias favoring affirmative studies. Meta-analysis of non-affirmative studies complements an uncorrected meta-analysis and other publication bias analyses by accommodating small meta-analyses, non-normal effects, heterogeneous effects across studies, and additional forms of selective reporting (in particular, P-hacking).

  View details for DOI 10.1136/bmj-2023-076851

  View details for Web of Science ID 001196122100003

  View details for PubMedID 38490665

  View details for PubMedCentralID PMC10941077

• <i>P</i>-hacking in meta-analyses: A formalization and new meta-analytic methods RESEARCH SYNTHESIS METHODS Mathur, M. B. 2024; 15 (3): 483-499

  Abstract

  As traditionally conceived, publication bias arises from selection operating on a collection of individually unbiased estimates. A canonical form of such selection across studies (SAS) is the preferential publication of affirmative studies (i.e., those with significant, positive estimates) versus nonaffirmative studies (i.e., those with nonsignificant or negative estimates). However, meta-analyses can also be compromised by selection within studies (SWS), in which investigators "p-hack" results within their study to obtain an affirmative estimate. Published estimates can then be biased even conditional on affirmative status, which comprises the performance of existing methods that only consider SAS. We propose two new analysis methods that accommodate joint SAS and SWS; both analyze only the published nonaffirmative estimates. First, we propose estimating the underlying meta-analytic mean by fitting "right-truncated meta-analysis" (RTMA) to the published nonaffirmative estimates. This method essentially imputes the entire underlying distribution of population effects. Second, we propose conducting a standard meta-analysis of only the nonaffirmative studies (MAN); this estimate is conservative (negatively biased) under weakened assumptions. We provide an R package (phacking) and website (metabias.io). Our proposed methods supplement existing methods by assessing the robustness of meta-analyses to joint SAS and SWS.

  View details for DOI 10.1002/jrsm.1701

  View details for Web of Science ID 001150946600001

  View details for PubMedID 38273211

  View details for PubMedCentralID PMC11042997

• Ethical drawbacks of sustainable meat choices SCIENCE Mathur, M. B. 2022; 375 (6587): 1362

  View details for DOI 10.1126/science.abo2535

  View details for Web of Science ID 000778894800029

  View details for PubMedID 35324309

• Methods to Address Confounding and Other Biases in Meta-Analyses: Review and Recommendations ANNUAL REVIEW OF PUBLIC HEALTH Mathur, M. B., VanderWeele, T. J. 2022; 43: 19-35

  Abstract

  Meta-analyses contribute critically to cumulative science, but they can produce misleading conclusions if their constituent primary studies are biased, for example by unmeasured confounding in nonrandomized studies. We provide practical guidance on how meta-analysts can address confounding and other biases that affect studies' internal validity, focusing primarily on sensitivity analyses that help quantify how biased the meta-analysis estimates might be. We review a number of sensitivity analysis methods to do so, especially recent developments that are straightforward to implement and interpret and that use somewhat less stringent statistical assumptions than do earlier methods. We give recommendations for how these newer methods could be applied in practice and illustrate using a previously published meta-analysis. Sensitivity analyses can provide informative quantitative summaries of evidence strength, and we suggest reporting them routinely in meta-analyses of potentially biased studies. This recommendation in no way diminishes the importance of defining study eligibility criteria that reduce bias and of characterizing studies' risks of bias qualitatively.

  View details for DOI 10.1146/annurev-publhealth-051920-114020

  View details for Web of Science ID 000789889200002

  View details for PubMedID 34535060

  View details for PubMedCentralID PMC8959012

• Investigating the replicability of preclinical cancer biology. eLife Errington, T. M., Mathur, M., Soderberg, C. K., Denis, A., Perfito, N., Iorns, E., Nosek, B. A. 2021; 10

  Abstract

  Replicability is an important feature of scientific research, but aspects of contemporary research culture, such as an emphasis on novelty, can make replicability seem less important than it should be. The Reproducibility Project: Cancer Biology was set up to provide evidence about the replicability of preclinical research in cancer biology by repeating selected experiments from high-impact papers. A total of 50 experiments from 23 papers were repeated, generating data about the replicability of a total of 158 effects. Most of the original effects were positive effects (136), with the rest being null effects (22). A majority of the original effect sizes were reported as numerical values (117), with the rest being reported as representative images (41). We employed seven methods to assess replicability, and some of these methods were not suitable for all the effects in our sample. One method compared effect sizes: for positive effects, the median effect size in the replications was 85% smaller than the median effect size in the original experiments, and 92% of replication effect sizes were smaller than the original. The other methods were binary - the replication was either a success or a failure - and five of these methods could be used to assess both positive and null effects when effect sizes were reported as numerical values. For positive effects, 40% of replications (39/97) succeeded according to three or more of these five methods, and for null effects 80% of replications (12/15) were successful on this basis; combining positive and null effects, the success rate was 46% (51/112). A successful replication does not definitively confirm an original finding or its theoretical interpretation. Equally, a failure to replicate does not disconfirm a finding, but it does suggest that additional investigation is needed to establish its reliability.

  View details for DOI 10.7554/eLife.71601

  View details for PubMedID 34874005

  View details for PubMedCentralID PMC8651293

• Menopausal hormone therapy and women's health: An umbrella review. PLoS medicine Zhang, G., Chen, J., Luo, Y., Mathur, M. B., Anagnostis, P., Nurmatov, U., Talibov, M., Zhang, J., Hawrylowicz, C. M., Lumsden, M. A., Critchley, H., Sheikh, A., Lundback, B., Lasser, C., Kankaanranta, H., Lee, S. H., Nwaru, B. I. 2021; 18 (8): e1003731

  Abstract

  BACKGROUND: There remains uncertainty about the impact of menopausal hormone therapy (MHT) on women's health. A systematic, comprehensive assessment of the effects on multiple outcomes is lacking. We conducted an umbrella review to comprehensively summarize evidence on the benefits and harms of MHT across diverse health outcomes.METHODS AND FINDINGS: We searched MEDLINE, EMBASE, and 10 other databases from inception to November 26, 2017, updated on December 17, 2020, to identify systematic reviews or meta-analyses of randomized controlled trials (RCTs) and observational studies investigating effects of MHT, including estrogen-alone therapy (ET) and estrogen plus progestin therapy (EPT), in perimenopausal or postmenopausal women in all countries and settings. All health outcomes in previous systematic reviews were included, including menopausal symptoms, surrogate endpoints, biomarkers, various morbidity outcomes, and mortality. Two investigators independently extracted data and assessed methodological quality of systematic reviews using the updated 16-item AMSTAR 2 instrument. Random-effects robust variance estimation was used to combine effect estimates, and 95% prediction intervals (PIs) were calculated whenever possible. We used the term MHT to encompass ET and EPT, and results are presented for MHT for each outcome, unless otherwise indicated. Sixty systematic reviews were included, involving 102 meta-analyses of RCTs and 38 of observational studies, with 102 unique outcomes. The overall quality of included systematic reviews was moderate to poor. In meta-analyses of RCTs, MHT was beneficial for vasomotor symptoms (frequency: 9 trials, 1,104 women, risk ratio [RR] 0.43, 95% CI 0.33 to 0.57, p < 0.001; severity: 7 trials, 503 women, RR 0.29, 95% CI 0.17 to 0.50, p = 0.002) and all fracture (30 trials, 43,188 women, RR 0.72, 95% CI 0.62 to 0.84, p = 0.002, 95% PI 0.58 to 0.87), as well as vaginal atrophy (intravaginal ET), sexual function, vertebral and nonvertebral fracture, diabetes mellitus, cardiovascular mortality (ET), and colorectal cancer (EPT), but harmful for stroke (17 trials, 37,272 women, RR 1.17, 95% CI 1.05 to 1.29, p = 0.027) and venous thromboembolism (23 trials, 42,292 women, RR 1.60, 95% CI 0.99 to 2.58, p = 0.052, 95% PI 1.03 to 2.99), as well as cardiovascular disease incidence and recurrence, cerebrovascular disease, nonfatal stroke, deep vein thrombosis, gallbladder disease requiring surgery, and lung cancer mortality (EPT). In meta-analyses of observational studies, MHT was associated with decreased risks of cataract, glioma, and esophageal, gastric, and colorectal cancer, but increased risks of pulmonary embolism, cholelithiasis, asthma, meningioma, and thyroid, breast, and ovarian cancer. ET and EPT had opposite effects for endometrial cancer, endometrial hyperplasia, and Alzheimer disease. The major limitations include the inability to address the varying effects of MHT by type, dose, formulation, duration of use, route of administration, and age of initiation and to take into account the quality of individual studies included in the systematic reviews. The study protocol is publicly available on PROSPERO (CRD42017083412).CONCLUSIONS: MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor.

  View details for DOI 10.1371/journal.pmed.1003731

  View details for PubMedID 34339416

• Interventions to Reduce Meat Consumption by Appealing to Animal Welfare: Meta-Analysis and Evidence-Based Recommendations. Appetite Mathur, M. B., Peacock, J., Reichling, D. B., Nadler, J., Bain, P. A., Gardner, C. D., Robinson, T. N. 2021: 105277

  Abstract

  Reducing meat consumption may improve human health, curb environmental damage, and limit the large-scale suffering of animals reared in factory farms. Most attention to reducing consumption has focused on restructuring environments where foods are chosen or on making health or environmental appeals. However, psychological theory suggests that interventions appealing to animal welfare concerns might operate on distinct, potent pathways. We conducted a systematic review and meta-analysis evaluating the effec-tiveness of these interventions. We searched eight academic databases and extensively searched grey literature. We meta-analyzed 100 studies assessing interventions designed to reduce meat consumption or purchase by mentioning or portraying farm animals, that measured behavioral or self-reported outcomes related to meat consumption, purchase, or related intentions, and that had a control condition. The interventions consistently reduced meat consumption, purchase, or related intentions at least in the short term with meaningfully large effects (meta-analytic mean risk ratio [RR] = 1.22; 95% CI: [1.13, 1.33]). We estimated that a large majority of true population effects (71%; 95% CI: [59%, 80%]) were stronger than RR = 1.1 and that few were in the unintended direction. Via meta-regression, we identified some specific characteristics of studies and interventions that were associated with effect size. Risk-of-bias assessments identified both methodological strengths and limitations of this literature; however, results did not differ meaningfully in sensitivity analyses retaining only studies at the lowest risk of bias. Evidence of publication bias was not apparent. In conclusion, animal welfare inter-ventions preliminarily appear effective in these typically short-term studies of primarily self-reported outcomes. Future research should use direct behavioral outcomes that mini-mize the potential for social desirability bias and are measured over long-term follow-up.

  View details for DOI 10.1016/j.appet.2021.105277

  View details for PubMedID 33984401

• Sensitivity analysis for publication bias in meta-analyses JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES C-APPLIED STATISTICS Mathur, M. B., VanderWeele, T. J. 2020; 69 (5): 1091-1119

  Abstract

  We propose sensitivity analyses for publication bias in meta-analyses. We consider a publication process such that 'statistically significant' results are more likely to be published than negative or "non-significant" results by an unknown ratio, η. Our proposed methods also accommodate some plausible forms of selection based on a study's standard error. Using inverse probability weighting and robust estimation that accommodates non-normal population effects, small meta-analyses, and clustering, we develop sensitivity analyses that enable statements such as 'For publication bias to shift the observed point estimate to the null, "significant" results would need to be at least 30 fold more likely to be published than negative or "non-significant" results'. Comparable statements can be made regarding shifting to a chosen non-null value or shifting the confidence interval. To aid interpretation, we describe empirical benchmarks for plausible values of η across disciplines. We show that a worst-case meta-analytic point estimate for maximal publication bias under the selection model can be obtained simply by conducting a standard meta-analysis of only the negative and 'non-significant' studies; this method sometimes indicates that no amount of such publication bias could 'explain away' the results. We illustrate the proposed methods by using real meta-analyses and provide an R package: PublicationBias.

  View details for DOI 10.1111/rssc.12440

  View details for Web of Science ID 000563276900001

  View details for PubMedID 33132447

  View details for PubMedCentralID PMC7590147

• Finding Common Ground in Meta-Analysis "Wars" on Violent Video Games PERSPECTIVES ON PSYCHOLOGICAL SCIENCE Mathur, M. B., VanderWeele, T. J. 2019; 14 (4): 705-708

  Abstract

  Independent meta-analyses on the same topic can sometimes yield seemingly conflicting results. For example, prominent meta-analyses assessing the effects of violent video games on aggressive behavior have reached apparently different conclusions, provoking ongoing debate. We suggest that such conflicts are sometimes partly an artifact of reporting practices for meta-analyses that focus only on the pooled point estimate and its statistical significance. Considering statistics that focus on the distributions of effect sizes and that adequately characterize effect heterogeneity can sometimes indicate reasonable consensus between "warring" meta-analyses. Using novel analyses, we show that this seems to be the case in the video-game literature. Despite seemingly conflicting results for the statistical significance of the pooled estimates in different meta-analyses of video-game studies, all of the meta-analyses do in fact point to the conclusion that, in the vast majority of settings, violent video games do increase aggressive behavior but that these effects are almost always quite small.

  View details for DOI 10.1177/1745691619850104

  View details for Web of Science ID 000474242600013

  View details for PubMedID 31188714

  View details for PubMedCentralID PMC6904227

• Sensitivity Analysis for Unmeasured Confounding in Meta-Analyses JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION Mathur, M. B., VanderWeele, T. J. 2020; 115 (529): 163-172

  Abstract

  Random-effects meta-analyses of observational studies can produce biased estimates if the synthesized studies are subject to unmeasured confounding. We propose sensitivity analyses quantifying the extent to which unmeasured confounding of specified magnitude could reduce to below a certain threshold the proportion of true effect sizes that are scientifically meaningful. We also develop converse methods to estimate the strength of confounding capable of reducing the proportion of scientifically meaningful true effects to below a chosen threshold. These methods apply when a "bias factor" is assumed to be normally distributed across studies or is assessed across a range of fixed values. Our estimators are derived using recently proposed sharp bounds on confounding bias within a single study that do not make assumptions regarding the unmeasured confounders themselves or the functional form of their relationships with the exposure and outcome of interest. We provide an R package, EValue, and a free website that compute point estimates and inference and produce plots for conducting such sensitivity analyses. These methods facilitate principled use of random-effects meta-analyses of observational studies to assess the strength of causal evidence for a hypothesis.

  View details for DOI 10.1080/01621459.2018.1529598

  View details for Web of Science ID 000469705900001

  View details for PubMedID 32981992

  View details for PubMedCentralID PMC7518377

• New metrics for meta-analyses of heterogeneous effects STATISTICS IN MEDICINE Mathur, M. B., VanderWeele, T. J. 2019; 38 (8): 1336-1342

  Abstract

  We provide two simple metrics that could be reported routinely in random-effects meta-analyses to convey evidence strength for scientifically meaningful effects under effect heterogeneity (ie, a nonzero estimated variance of the true effect distribution). First, given a chosen threshold of meaningful effect size, meta-analyses could report the estimated proportion of true effect sizes above this threshold. Second, meta-analyses could estimate the proportion of effect sizes below a second, possibly symmetric, threshold in the opposite direction from the estimated mean. These metrics could help identify if (1) there are few effects of scientifically meaningful size despite a "statistically significant" pooled point estimate, (2) there are some large effects despite an apparently null point estimate, or (3) strong effects in the direction opposite the pooled estimate also regularly occur (and thus, potential effect modifiers should be examined). These metrics should be presented with confidence intervals, which can be obtained analytically or, under weaker assumptions, using bias-corrected and accelerated bootstrapping. Additionally, these metrics inform relative comparison of evidence strength across related meta-analyses. We illustrate with applied examples and provide an R function to compute the metrics and confidence intervals.

  View details for DOI 10.1002/sim.8057

  View details for Web of Science ID 000460319700003

  View details for PubMedID 30513552

  View details for PubMedCentralID PMC6519385

• Web Site and R Package for Computing E-values EPIDEMIOLOGY Mathur, M. B., Ding, P., Riddell, C. A., VanderWeele, T. J. 2018; 29 (5): E45-E47

  View details for DOI 10.1097/EDE.0000000000000864

  View details for Web of Science ID 000441143500006

  View details for PubMedID 29912013

  View details for PubMedCentralID PMC6066405

• Data availability, reusability, and analytic reproducibility: evaluating the impact of a mandatory open data policy at the journal Cognition. Royal Society open science Hardwicke, T. E., Mathur, M. B., MacDonald, K., Nilsonne, G., Banks, G. C., Kidwell, M. C., Hofelich Mohr, A., Clayton, E., Yoon, E. J., Henry Tessler, M., Lenne, R. L., Altman, S., Long, B., Frank, M. C. 2018; 5 (8): 180448

  Abstract

  Access to data is a critical feature of an efficient, progressive and ultimately self-correcting scientific ecosystem. But the extent to which in-principle benefits of data sharing are realized in practice is unclear. Crucially, it is largely unknown whether published findings can be reproduced by repeating reported analyses upon shared data ('analytic reproducibility'). To investigate this, we conducted an observational evaluation of a mandatory open data policy introduced at the journal Cognition. Interrupted time-series analyses indicated a substantial post-policy increase in data available statements (104/417, 25% pre-policy to 136/174, 78% post-policy), although not all data appeared reusable (23/104, 22% pre-policy to 85/136, 62%, post-policy). For 35 of the articles determined to have reusable data, we attempted to reproduce 1324 target values. Ultimately, 64 values could not be reproduced within a 10% margin of error. For 22 articles all target values were reproduced, but 11 of these required author assistance. For 13 articles at least one value could not be reproduced despite author assistance. Importantly, there were no clear indications that original conclusions were seriously impacted. Mandatory open data policies can increase the frequency and quality of data sharing. However, suboptimal data curation, unclear analysis specification and reporting errors can impede analytic reproducibility, undermining the utility of data sharing and the credibility of scientific findings.

  View details for DOI 10.1098/rsos.180448

  View details for PubMedID 30225032

  View details for PubMedCentralID PMC6124055

• PSYCHOLOGY Estimating the reproducibility of psychological science SCIENCE Aarts, A. A., Anderson, J. E., Anderson, C. J., Attridge, P. R., Attwood, A., Axt, J., Babel, M., Bahnik, S., Baranski, E., Barnett-Cowan, M., Bartmess, E., Beer, J., Bell, R., Bentley, H., Beyan, L., Binion, G., Borsboom, D., Bosch, A., Bosco, F. A., Bowman, S. D., Brandt, M. J., Braswell, E., Brohmer, H., Brown, B. T., Brown, K., Bruening, J., Calhoun-Sauls, A., Callahan, S. P., Chagnon, E., Chandler, J., Chartier, C. R., Cheung, F., Christopherson, C. D., Cillessen, L., Clay, R., Cleary, H., Cloud, M. D., Cohn, M., Cohoon, J., Columbus, S., Cordes, A., Costantini, G., Alvarez, L. D., Cremata, E., Crusius, J., DeCoster, J., DeGaetano, M. A., Della Penna, N., den Bezemer, B., Deserno, M. K., Devitt, O., Dewitte, L., Dobolyi, D. G., Dodson, G. T., Donnellan, M. B., Donohue, R., Dore, R. A., Dorrough, A., Dreber, A., Dugas, M., Dunn, E. W., Easey, K., Eboigbe, S., Eggleston, C., Embley, J., Epskamp, S., Errington, T. M., Estel, V., Farach, F. J., Feather, J., Fedor, A., Fernandez-Castilla, B., Fiedler, S., Field, J. G., Fitneva, S. A., Flagan, T., Forest, A. L., Forsell, E., Foster, J. D., Frank, M. C., Frazier, R. S., Fuchs, H., Gable, P., Galak, J., Galliani, E. M., Gampa, A., Garcia, S., Gazarian, D., Gilbert, E., Giner-Sorolla, R., Gloeckner, A., Goellner, L., Goh, J. X., Goldberg, R., Goodbourn, P. T., Gordon-McKeon, S., Gorges, B., Gorges, J., Goss, J., Graham, J., Grange, J. A., Gray, J., Hartgerink, C., Hartshorne, J., Hasselman, F., Hayes, T., Heikensten, E., Henninger, F., Hodsoll, J., Holubar, T., Hoogendoorn, G., Humphries, D. J., Hung, C. O., Immelman, N., Irsik, V. C., Jahn, G., Jaekel, F., Jekel, M., Johannesson, M., Johnson, L. G., Johnson, D. J., Johnson, K. M., Johnston, W. J., Jonas, K., Joy-Gaba, J. A., Kappes, H. B., Kelso, K., Kidwell, M. C., Kim, S. K., Kirkhart, M., Kleinberg, B., Knezevic, G., Kolorz, F. M., Kossakowski, J. J., Krause, R. W., Krijnen, J., Kuhlmann, T., Kunkels, Y. K., Kyc, M. M., Lai, C. K., Laique, A., Lakens, D., Lane, K. A., Lassetter, B., Lazarevic, L. B., LeBel, E. P., Lee, K. J., Lee, M., Lemm, K., Levitan, C. A., Lewis, M., Lin, L., Lin, S., Lippold, M., Loureiro, D., Luteijn, I., Mackinnon, S., Mainard, H. N., Marigold, D. C., Martin, D. P., Martinez, T., Masicampo, E. J., Matacotta, J., Mathur, M., May, M., Mechin, N., Mehta, P., Meixner, J., Melinger, A., Miller, J. K., Miller, M., Moore, K., Moeschl, M., Motyl, M., Mueller, S. M., Munafo, M., Neijenhuijs, K. I., Nervi, T., Nicolas, G., Nilsonne, G., Nosek, B. A., Nuijten, M. B., Olsson, C., Osborne, C., Ostkamp, L., Pavel, M., Penton-Voak, I. S., Perna, O., Pernet, C., Perugini, M., Pipitone, R. N., Pitts, M., Plessow, F., Prenoveau, J. M., Rahal, R., Ratliff, K. A., Reinhard, D., Renkewitz, F., Ricker, A. A., Rigney, A., Rivers, A. M., Roebke, M., Rutchick, A. M., Ryan, R. S., Sahin, O., Saide, A., Sandstrom, G. M., Santos, D., Saxe, R., Schlegelmilch, R., Schmidt, K., Scholz, S., Seibel, L., Selterman, D. F., Shaki, S., Simpson, W. B., Sinclair, H. C., Skorinko, J. L., Slowik, A., Snyder, J. S., Soderberg, C., Sonnleitner, C., Spencer, N., Spies, J. R., Steegen, S., Stieger, S., Strohminger, N., Sullivan, G. B., Talhelm, T., Tapia, M., te Dorsthorst, A., Thomae, M., Thomas, S. L., Tio, P., Traets, F., Tsang, S., Tuerlinckx, F., Turchan, P., Valasek, M., van 't Veer, A. E., Van Aert, R., van Assen, M., van Bork, R., van de Ven, M., van den Bergh, D., van der Hulst, M., van Dooren, R., van Doorn, J., van Renswoude, D. R., van Rijn, H., Vanpaemel, W., Echeverria, A. V., Vazquez, M., Velez, N., Vermue, M., Verschoor, M., Vianello, M., Voracek, M., Vuu, G., Wagenmakers, E., Weerdmeester, J., Welsh, A., Westgate, E. C., Wissink, J., Wood, M., Woods, A., Wright, E., Wu, S., Zeelenberg, M., Zuni, K. 2015; 349 (6251)

  Abstract

  Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams.

  View details for DOI 10.1126/science.aac4716

  View details for Web of Science ID 000360646800042

• Effect of a portion-size default nudge on meat consumption and diner satisfaction: controlled experiments in Stanford University dining halls BMC PUBLIC HEALTH Voski, A., Braginsky, M., Zhang, A., Bertoldo, J., Egan, S., Levig, L. A., Ihrig, M., Mathur, M. B. 2025; 25 (1): 1434

  Abstract

  Reducing meat consumption, especially in high-intake countries such as the United States, is crucial in mitigating the climate and biodiversity crises and improving public health and animal welfare. Choice-architecture interventions or nudges in the food domain, such as choice defaults (e.g., reduced default portion sizes), can be powerful levers of behavior change. However, evidence remains limited in large-scale, real-life settings, and little is known about potential effects on diner satisfaction and backfiring effects that reduce or even reverse the desired behavior. These uncertainties have posed substantial barriers to scalability and wider adoption by the food service industry. In our single-blinded, quasi-experimental, pre-registered field interventions in Stanford University dining halls with staff-served portions, a 25% reduction in the serving spoon size (Study 1, 24 days, 364 diners, made-to-order burritos) produced a non-significant trend of 18% less meat served per day without reducing overall diner satisfaction (p = 0.059, d = 0.64) but with a wide CI that included the null (- 49.2, 1.07). A more substantial 50% reduction in serving spoon size (Study 2, 29 days, 1802 diners, varying menu items) did not reduce the amount of meat served (p = 0.60, d = 0.20), triggered backfiring effects, and significantly decreased diner satisfaction. Combining the two studies, the intervention did not significantly reduce meat consumption. While the trends in our findings are consistent with the 'norm range model'-i.e., that moderate portion reductions may decrease intake but drastic reductions may prompt compensatory eating-key differences and contextual nuances between the two studies help explain the mixed results. Future studies on the 'norm range' of default portion size nudges to reduce meat consumption across different menu items and food service models is suggested to increase our understanding of effective and scalable interventions that facilitate collective shifts towards more sustainable dietary behaviors.

  View details for DOI 10.1186/s12889-025-22495-9

  View details for Web of Science ID 001470264400002

  View details for PubMedID 40241017

  View details for PubMedCentralID PMC12001533

• Pitfalls of imputing using incomplete auxiliary variables. American journal of epidemiology Mathur, M. B., Shpitser, I. 2025

  View details for DOI 10.1093/aje/kwaf043

  View details for PubMedID 40207659

• Meaningfully reducing consumption of meat and animal products is an unsolved problem: A meta-analysis. Research square Green, S. A., Smith, B., Mathur, M. B. 2025

  Abstract

  Which interventions produce the largest and most enduring reductions in consumption of meat and animal products (MAP)? We address this question with a theoretical review and meta-analysis of randomized controlled trials that measured MAP consumption at least one day after intervention. We meta-analyze 35 papers comprising 41 studies, 112 interventions, and approximately 87,000 subjects. We find that these papers employ four major strategies to change behavior: choice architecture, persuasion, psychology, and a combination of persuasion and psychology. The pooled effect of all 112 interventions on MAP consumption is quite small (standardized mean difference [SMD] = 0.07 (95% CI: [0.02, 0.12]), indicating an unsolved problem. Interventions aiming to reduce only consumption of red and processed meat were more effective (SMD = 0.25; 95% CI: [0.11, 0.38]), but it remains unclear whether such interventions also decrease consumption of other forms of MAP. We conclude that while existing approaches do not provide a proven remedy to MAP consumption, designs and measurement strategies have generally been improving over time, and many promising interventions await rigorous evaluation.

  View details for DOI 10.21203/rs.3.rs-5486065/v1

  View details for PubMedID 40166031

  View details for PubMedCentralID PMC11957195

• Observational research in epidemic settings: a roadmap to reform. BMJ global health Ricotta, E. E., Bustos Carrillo, F. A., Angelli-Nichols, S., Barugahare, J., Benton, A., Carlson, C. J., Chang-Rabley, E., Dean, N. E., Duda, S. N., Federer, L., Fill, M. A., LeRoy, E. C., Linton, N. M., Lipsitch, M., Mathur, M. B., Phelan, A. L., Rid, A., Rosen, J. B., Sauer, L., Sullivan, S. G., Zendt, M., Evans, N. 2025; 10 (2)

  Abstract

  Observational studies are critical tools in clinical research and public health response, but challenges arise in ensuring the data produced by these studies are scientifically robust and socially valuable. Resolving these challenges requires careful attention to prioritising the most valuable research questions, ensuring robust study design, strong data management practices, expansive community engagement, and access and benefit sharing of results and research materials. This paper opens with a discussion of how well-designed observational studies contribute to biomedical evidence and provides examples from across the clinical literature of how these methods generate hypotheses for future research and uncover otherwise unattainable insights by providing examples from across the clinical literature. Then, we present obstacles that remain in ensuring observational studies are optimally designed, conducted and communicated.

  View details for DOI 10.1136/bmjgh-2024-017981

  View details for PubMedID 39929534

  View details for PubMedCentralID PMC11815396

• Mathur and Shpitser respond to "The evolution of selection bias in the recent epidemiologic literature-a selective overview" AMERICAN JOURNAL OF EPIDEMIOLOGY Mathur, M. B., Shpitser, I. 2025; 194 (3): 585-586

  View details for DOI 10.1093/aje/kwae287

  View details for Web of Science ID 001390355100001

  View details for PubMedID 39214648

  View details for PubMedCentralID PMC11879549

• On the Statistical Analysis of Experiments With Manipulation Checks ADVANCES IN METHODS AND PRACTICES IN PSYCHOLOGICAL SCIENCE Mathur, M. B. 2025; 8 (1)

  View details for DOI 10.1177/25152459241297537

  View details for Web of Science ID 001398158700001

• Population Trends and Individual Fluidity of Sexual Identity Among Stockholm County Residents. JAMA network open Zhang, W., Tynelius, P., Mathur, M. B., Quartagno, M., Brandén, G., Liljeros, F., Kosidou, K. 2024; 7 (12): e2447627

  View details for DOI 10.1001/jamanetworkopen.2024.47627

  View details for PubMedID 39630454

  View details for PubMedCentralID PMC11618470

• Nurse Burnout and Patient Safety, Satisfaction, and Quality of Care: A Systematic Review and Meta-Analysis. JAMA network open Li, L. Z., Yang, P., Singer, S. J., Pfeffer, J., Mathur, M. B., Shanafelt, T. 2024; 7 (11): e2443059

  Abstract

  Occupational burnout syndrome is characterized by emotional exhaustion, depersonalization, and a diminished sense of personal accomplishment and is prevalent among nurses. Although previous meta-analyses have explored the correlates of nurse burnout, none have estimated their association with health care quality and safety and patient morbidity and mortality.To evaluate the magnitude and moderators of the association between nurse burnout and patient safety, patient satisfaction, and quality of care.The Web of Science, Scopus, MEDLINE, Embase, PsycINFO, CINAHL, and ProQuest databases were searched from January 1, 1994, to February 29, 2024.Two reviewers independently identified studies that reported a quantifiable association between nurse burnout and any of the outcomes of patient safety, patient satisfaction, or quality of health care.The PRISMA 2020 guideline was followed. Two reviewers independently extracted the standardized mean difference (SMD) (Cohen d) estimates for a random-effects meta-analysis. Subgroup analyses and meta-regressions were conducted using prespecified variables.Any measure of patient safety, patient satisfaction, or quality of health care previously associated with nurse burnout.A total of 85 studies (81 cross-sectional and 4 longitudinal) involving 288 581 nurses from 32 countries (mean [SD] age, 33.9 (2.1) years; 82.7% female; mean [SD] burnout prevalence rate with study-specific ascertainments, 30.7% [9.7%]) were included. Nurse burnout was associated with a lower safety climate or culture (SMD, -0.68; 95% CI, -0.83 to -0.54), lower safety grade (SMD, -0.53; 95% CI, -0.72 to -0.34), and more frequent nosocomial infections (SMD, -0.20; 95% CI, -0.36 to -0.04), patient falls (SMD, -0.12; 95% CI, -0.22 to -0.03), medication errors (SMD, -0.30; 95% CI, -0.48 to -0.11), adverse events or patient safety incidents (SMD, -0.42; 95% CI, -0.76 to -0.07), and missed care or care left undone (SMD, -0.58; 95% CI, -0.91 to -0.26) but not with the frequency of pressure ulcers. Nurse burnout was also associated with lower patient satisfaction ratings (SMD, -0.51; 95% CI, -0.86 to -0.17) but not with the frequencies of patient complaints or patient abuse. Finally, nurse burnout was associated with lower nurse-assessed quality of care (SMD, -0.44; 95% CI, -0.57 to -0.30) but not with standardized mortality rate. The associations were consistent across nurses' age, sex, work experience, and geography and persistent over time. For patient safety outcomes, the association was smaller for the low personal accomplishment subcomponent of burnout than for emotional exhaustion or depersonalization, as well as for nurses with a college education.In this systematic review and meta-analysis, nurse burnout was found to be associated with lower health care quality and safety and lower patient satisfaction. This association was consistent across nurse and study characteristics.

  View details for DOI 10.1001/jamanetworkopen.2024.43059

  View details for PubMedID 39499515

• Increased Emergency Department Identification of Young People Experiencing Trafficking During the COVID-19 Pandemic: An Interrupted Time-Series Analysis. Public health reports (Washington, D.C. : 1974) Panda, P., Deng, Y., Fang, A., Ward, V., Wang, E., Newberry, J., Mathur, M., Patel, A. 2024: 333549241279662

  Abstract

  Human trafficking is a public health issue affecting young people across the United States, and trafficked young people frequently present to emergency departments (EDs). The identification of trafficked young people by pediatric EDs during the COVID-19 pandemic is not well understood. We examined trends in the identification of young people with current or lifetime experiences of trafficking in US pediatric EDs before and during the COVID-19 pandemic.We performed an interrupted time-series analysis using the Pediatric Health Information System database, which includes data from 49 US children's hospitals, to determine differences in rates of trafficked young people identified in pediatric EDs before and during the COVID-19 pandemic.We included 910 patients; 255 prepandemic (October 1, 2018, through February 29, 2020) and 655 during the COVID-19 pandemic (March 1, 2020, through February 28, 2023). We found a 1.92-fold increase in the incidence rate of identified trafficked young people at the start of the COVID-19 pandemic in March 2020 (incidence rate ratio = 1.92; 95% CI, 1.47-2.51; P < .001), followed by a decrease over time.The observed increase in identified trafficked young people during the onset of the COVID-19 pandemic should alert pediatric ED providers to the opportunity to identify and provide services for trafficked young people as an important part of improving preparedness for future disease outbreaks. Our observed identification trends do not represent the true incidence of trafficked young people presenting to pediatric EDs during the COVID-19 pandemic. Future work should seek to better understand the true occurrence and the health and service needs of trafficked young people during emergencies.

  View details for DOI 10.1177/00333549241279662

  View details for PubMedID 39344051

• Reanalysis of "A longitudinal study of meat reduction over time in the UK" FOOD QUALITY AND PREFERENCE Winslow, J., Mathur, M. B. 2025; 123

  View details for DOI 10.1016/j.foodqual.2024.105324

  View details for Web of Science ID 001321299900001

• A Randomized Controlled Trial of a Brief Self-Directed Secular REACH Forgiveness Intervention With Indonesian Christians: Does Religiousness Matter? SPIRITUALITY IN CLINICAL PRACTICE Kurniati, N., Cowden, R. G., Zulkaida, A., Gunatirin, E. Y., Rahardjo, W., Elisabeth, M. P., Suryani, A., Cynthia, T., Rini, Q., Mathur, M. B., Ho, M., VanderWeele, T. J., Worthington Jr, E. L. 2024; 11 (3): 297-314

  View details for DOI 10.1037/scp0000374

  View details for Web of Science ID 001302535000006

• Considering pregnancies as repeated versus independent events: An empirical comparison of common approaches across selected perinatal outcomes. American journal of obstetrics & gynecology MFM Bane, S., Carmichael, S. L., Mathur, M. B., Simard, J. F. 2024: 101434

  Abstract

  In population-based research, pregnancy may be a repeated event. Despite published guidance on how to address repeated pregnancies to the same individual, a variety of approaches are observed in perinatal epidemiological studies. While some of these approaches are supported by the chosen research question, others are consequences of constraints inherent to a given dataset (e.g., missing parity information). These decisions determine how appropriately a given research question can be answered and overall generalizability.To compare common cohort selection and analytic approaches used for perinatal epidemiological research by assessing the prevalence of two perinatal outcomes and their association with a clinical and a social independent variable STUDY DESIGN: Using vital records linked to maternal hospital discharge records for singleton births, we created four cohorts: (1) all-births (2) randomly selected one birth per individual (3) first observed birth per individual (4) primiparous-births (parity 1). Sampling of births was not conditional on cluster (i.e., we did not sample all births by a given mother, but rather sampled individual births). Study outcomes were severe maternal morbidity and preeclampsia/eclampsia, and the independent variables were self-reported race/ethnicity (as a social factor) and systemic lupus erythematosus. Comparing the four cohorts, we assessed the distribution of maternal characteristics, the prevalence of outcomes, overall and stratified by parity, and risk ratios for the associations of outcomes with independent variables. Among all-births, we then compared risk ratios from three analytic strategies: with standard inference that assumes independently sampled births to the same mother in the model, with cluster-robust inference, and adjusting for parity.We observed minor differences in the population characteristics between the all-birth (N=2,736,693), random-selection, and first-observed birth cohorts (both N=2,284,660), with more substantial differences between these cohorts and the primiparous-births cohort (N=1,054,684). Outcome prevalence was consistently lowest among all-births and highest among primiparous-births (e.g., severe maternal morbidity 18.9 per 1,000 births among primiparous-births vs. 16.6 per 1,000 births among all-births). When stratified by parity, outcome prevalence was always the lowest in births of parity 2 and highest among births of parity 1 for both outcomes. Risk ratios differed for study outcomes across all four cohorts, with the most pronounced differences between the primiparous-birth cohort and other cohorts. Among all-births, robust inference minimally impacted the confidence bounds of estimates, compared to the standard inference, i.e., crude estimates (e.g., lupus-severe maternal morbidity association: 4.01, 95% CI 3.54-4.55 vs. 4.01, 95% CI 3.53-4.56 for crude estimate), while adjusting for parity slightly shifted estimates, towards the null for severe maternal morbidity and away from the null for preeclampsia/eclampsia.Researchers should consider the alignment between the methods they use, their sampling strategy, and their research question. This could include refining the research question to better match inference possible for available data, considering alternative data sources, and appropriately noting data limitations and resulting bias, as well as the generalizability of findings. If parity is an established effect modifier, stratified results should be presented.

  View details for DOI 10.1016/j.ajogmf.2024.101434

  View details for PubMedID 38996915

• International REACH forgiveness intervention: a multisite randomised controlled trial. BMJ public health Ho, M. Y., Worthington, E. L., Cowden, R. G., Bechara, A. O., Chen, Z. J., Gunatirin, E. Y., Joynt, S., Khalanskyi, V. V., Korzhov, H., Kurniati, N. M., Rodriguez, N., Anastasiya Salnykova, A., Shtanko, L., Tymchenko, S., Voytenko, V. L., Zulkaida, A., Mathur, M. B., VanderWeele, T. J. 2024; 2 (1): e000072

  Abstract

  To determine whether a brief self-directed forgiveness workbook intervention could alter forgiveness, depression symptoms, and anxiety symptoms.A multisite randomised waitlist-controlled trial was conducted among 4598 participants. Recruitment occurred from 11 February 2020 to 30 September 2021. Final follow-up occurred on 25 October 2021.Participants were recruited from community-based samples in sites in Colombia, Hong Kong, Indonesia, South Africa, and Ukraine.Individuals (n=7837) were screened for eligibility. For inclusion, participants needed to be ≥18 years and have experienced an interpersonal transgression. The analytic sample consisted of n=4598 participants, median age 26 and 73% female.At each site, participants were randomly assigned to either immediate receipt of a self-directed forgiveness workbook intervention, or to receipt after a 2 week delay.The primary outcomes were unforgiveness (Transgression-Related Interpersonal Motivations Inventory-18), depression symptoms, and anxiety symptoms (Brief Symptom Inventory-18) measured at 2 weeks following intervention assignment.At 2 weeks follow-up, unforgiveness was lower among the immediate-treatment group compared with the delayed-treatment group (standardised mean difference=-0.53 (95% CI=-0.58 to -0.47)); similar patterns were found for depression (standardised mean difference=-0.22 (95% CI=-0.28 to -0.16)) and anxiety symptoms (standardised mean difference=-0.21 (95% CI=-0.27 to -0.15)).A brief workbook intervention promoted forgiveness and reduced depression and anxiety symptoms. The promotion of forgiveness with such workbooks has the potential for widespread dissemination to improve global mental health.NCT04257773.

  View details for DOI 10.1136/bmjph-2023-000072

  View details for PubMedID 40018096

  View details for PubMedCentralID PMC11812785

• The Risk of Aircraft-Acquired SARS-CoV-2 Transmission during Commercial Flights: A Systematic Review. International journal of environmental research and public health Zhao, D., Cheng, S., Tsui, F. R., Mathur, M. B., Wang, C. J. 2024; 21 (6)

  Abstract

  The aircraft-acquired transmission of SARS-CoV-2 poses a public health risk. Following PRISMA guidelines, we conducted a systematic review and analysis of articles, published prior to vaccines being available, from 24 January 2020 to 20 April 2021 to identify factors important for transmission. Articles were included if they mentioned index cases and identifiable flight duration, and excluded if they discussed non-commercial aircraft, airflow or transmission models, cases without flight data, or that were unable to determine in-flight transmission. From the 15 articles selected for in-depth review, 50 total flights were analyzed by flight duration both as a categorical variable-short (<3 h), medium (3-6 h), or long flights (>6 h)-and as a continuous variable with case counts modeled by negative binomial regression. Compared to short flights without masking, medium and long flights without masking were associated with 4.66-fold increase (95% CI: [1.01, 21.52]; p < 0.0001) and 25.93-fold increase in incidence rates (95% CI: [4.1, 164]; p < 0.0001), respectively; long flights with enforced masking had no transmission reported. A 1 h increase in flight duration was associated with 1.53-fold (95% CI: [1.19, 1.66]; p < 0.001) increase in the incidence rate ratio (IRR) of cases. Masking should be considered for long flights.

  View details for DOI 10.3390/ijerph21060654

  View details for PubMedID 38928901

• Toward evidence-based communication on overweight body mass index and mortality BMC MEDICINE Mathur, M. B., Mathur, V. S. 2024; 22 (1): 183

  Abstract

  Reducing overweight and obesity has been a longstanding focus of public health messaging and physician-patient interactions. Clinical guidelines by major public health organizations describe both overweight and obesity as risk factors for mortality and other health conditions. Accordingly, a majority of primary care physicians believe that overweight BMI (even without obesity) strongly increases mortality risk.The current evidence base suggests that although both obese BMI and underweight BMI are consistently associated with increased all-cause mortality, overweight BMI (without obesity) is not meaningfully associated with increased mortality. In fact, a number of studies suggest modest protective, rather than detrimental, associations of overweight BMI with all-cause mortality. Given this current evidence base, clinical guidelines and physician perceptions substantially overstate all-cause mortality risks associated with the range of BMIs classified as "overweight" but not "obese." Discrepancies between evidence and communication regarding mortality raise the question of whether similar discrepancies exist for other health outcomes.Health communication that inaccurately conveys current evidence may do more harm than good; this applies to communication from health authorities to health practitioners as well as to communication from health practitioners to individual patients. We give three recommendations to better align health communication with the current evidence. First, recommendations to the public and health practitioners should distinguish overweight from obese BMI and at this time should not describe overweight BMI as a risk factor for all-cause mortality. Second, primary care physicians' widespread misconceptions about overweight BMI should be rectified. Third, the evidence basis for other potential risks or benefits of overweight BMI should be rigorously examined and incorporated appropriately into health communication.

  View details for DOI 10.1186/s12916-024-03402-2

  View details for Web of Science ID 001225923500003

  View details for PubMedID 38693530

  View details for PubMedCentralID PMC11062896

• Do Forgiveness Campaign Activities Improve Forgiveness, Mental Health, and Flourishing? International journal of public health Ortega Bechara, A., Chen, Z. J., Cowden, R. G., Worthington, E. L., Toussaint, L., Rodriguez, N., Guzman Murillo, H., Ho, M. Y., Mathur, M. B., VanderWeele, T. J. 2024; 69: 1605341

  Abstract

  Objectives: To evaluate the effectiveness of a forgiveness public health intervention at promoting forgiveness, mental health, and flourishing. Methods: Colombian students (N = 2,878) at a private, nonreligious university were exposed to a 4-week forgiveness community campaign and were assessed pre- and post-campaign. Results: Forgiveness, mental health, and flourishing outcomes showed improvements after the campaign. On average, participants reported engaging in 7.18 (SD = 3.99) of the 16 types of campaign activities. The number of types of campaign activities that participants engaged in evidenced a positive linear association with forgiveness, although some activities were more popular than others and some activities were more strongly associated with increased forgiveness. For depression, anxiety, and flourishing, engaging in more activities was generally associated with greater improvements, but the patterns were less consistent relative to forgiveness. Conclusion: This forgiveness public health intervention effectively promoted forgiveness, mental health, and flourishing. Effective campaigns in diverse communities involve promoting mental and physical health through forgiveness. However, recent conflict may hinder acceptance, necessitating political capital for leadership advocating forgiveness initiatives.

  View details for DOI 10.3389/ijph.2024.1605341

  View details for PubMedID 38524628

  View details for PubMedCentralID PMC10957572

• In silico identification of putative causal genetic variants. bioRxiv : the preprint server for biology He, Z., Chu, B., Yang, J., Gu, J., Chen, Z., Liu, L., Morrison, T., Belloy, M. E., Qi, X., Hejazi, N., Mathur, M., Le Guen, Y., Tang, H., Hastie, T., Ionita-Laza, I., Sabatti, C., Candes, E. 2024

  Abstract

  Understanding the causal genetic architecture of complex phenotypes is essential for future research into disease mechanisms and potential therapies. Despite the widespread availability of genome-wide data, existing methods to analyze genetic data still primarily focus on marginal association models, which fall short of fully capturing the polygenic nature of complex traits and elucidating biological causal mechanisms. Here we present a computationally efficient causal inference framework for genome-wide detection of putative causal variants underlying genetic associations. Our approach utilizes summary statistics from potentially overlapping studies as input, constructs in silico knockoff copies of summary statistics as negative controls to attenuate confounding effects induced by linkage disequilibrium, and employs efficient ultrahigh-dimensional sparse regression to jointly model all genetic variants across the genome. Our method is computationally efficient, requiring less than 15 minutes on a single CPU to analyze genome-wide summary statistics. In applications to a meta-analysis of ten large-scale genetic studies of Alzheimer's disease (AD) we identified 82 loci associated with AD, including 37 additional loci missed by conventional GWAS pipeline via marginal association testing. The identified putative causal variants achieve state-of-the-art agreement with massively parallel reporter assays and CRISPR-Cas9 experiments. Additionally, we applied the method to a retrospective analysis of large-scale genome-wide association studies (GWAS) summary statistics from 2013 to 2022. Results reveal the method's capacity to robustly discover additional loci for polygenic traits beyond conventional GWAS and pinpoint potential causal variants underpinning each locus (on average, 22.7% more loci and 78.7% fewer proxy variants), contributing to a deeper understanding of complex genetic architectures in post-GWAS analyses. We are making the discoveries and software freely available to the community and anticipate that routine end-to-end in silico identification of putative causal genetic variants will become an important tool that will facilitate downstream functional experiments and future research into disease etiology, as well as the exploration of novel therapeutic avenues.

  View details for DOI 10.1101/2024.02.28.582621

  View details for PubMedID 38464202

• Evidence for Infant-directed Speech Preference Is Consistent Across Large-scale, Multi-site Replication and Meta-analysis. Open mind : discoveries in cognitive science Zettersten, M., Cox, C., Bergmann, C., Tsui, A. S., Soderstrom, M., Mayor, J., Lundwall, R. A., Lewis, M., Kosie, J. E., Kartushina, N., Fusaroli, R., Frank, M. C., Byers-Heinlein, K., Black, A. K., Mathur, M. B. 2024; 8: 439-461

  Abstract

  There is substantial evidence that infants prefer infant-directed speech (IDS) to adult-directed speech (ADS). The strongest evidence for this claim has come from two large-scale investigations: i) a community-augmented meta-analysis of published behavioral studies and ii) a large-scale multi-lab replication study. In this paper, we aim to improve our understanding of the IDS preference and its boundary conditions by combining and comparing these two data sources across key population and design characteristics of the underlying studies. Our analyses reveal that both the meta-analysis and multi-lab replication show moderate effect sizes (d 0.35 for each estimate) and that both of these effects persist when relevant study-level moderators are added to the models (i.e., experimental methods, infant ages, and native languages). However, while the overall effect size estimates were similar, the two sources diverged in the effects of key moderators: both infant age and experimental method predicted IDS preference in the multi-lab replication study, but showed no effect in the meta-analysis. These results demonstrate that the IDS preference generalizes across a variety of experimental conditions and sampling characteristics, while simultaneously identifying key differences in the empirical picture offered by each source individually and pinpointing areas where substantial uncertainty remains about the influence of theoretically central moderators on IDS preference. Overall, our results show how meta-analyses and multi-lab replications can be used in tandem to understand the robustness and generalizability of developmental phenomena.

  View details for DOI 10.1162/opmi_a_00134

  View details for PubMedID 38665547

• Marital transitions during earlier adulthood and subsequent health and well-being in mid- to late-life among female nurses: An outcome-wide analysis. Global epidemiology Chen, Y., Mathur, M. B., Case, B. W., VanderWeele, T. J. 2023; 5: 100099

  Abstract

  Comparing outcomes for individuals remaining married to those for single or divorced individuals might overstate the positive effects of the decision to marry, since marriage carries an inherent risk of divorce and its associated negative outcomes. While a growing literature has examined marital transitions, confounding by past marital history remains a concern and only a limited set of outcomes have been examined. To address these issues, this study examined incident first-time marriage and incident divorce/separation in relation to multiple subsequent physical health, health behavior, psychological distress, and psychosocial well-being outcomes in a large sample of female nurses in the U.S.. Data from the Nurses' Health Study II were studied (1993 to 2015/2017 questionnaire wave, Nmarriage analyses=11,830, Ndivorce/separation analyses=73,018, interquartile range of baseline age=35 to 42years). A set of regression models were used to regress each outcome on marital transition status, adjusting for a wide range of initial health and wellbeing status in addition to other covariates. Bonferroni correction was performed to account for multiple testing. Among the initially never married, those who became married had lower mortality (RR=0.65, 95%CI=0.50, 0.84), lower risks of cardiovascular diseases (e.g., RRstroke=0.64, 95%CI=0.50, 0.82), greater psychological wellbeing and less psychological distress (e.g., SSdepressive symptoms=-0.10, 95%CI=-0.15, -0.06). Among the initially married, those who became divorced/separated had lower social integration (beta=-0.15, 95%CI=-0.19, -0.11), greater psychosocial distress (e.g., RRdepression=1.23, 95%CI=1.10, 1.37), and possibly greater risks of mortality, cardiovascular diseases, and smoking. Future research could study similar questions using data from more recent cohorts, examine potential mechanisms and heterogeneity, and also examine alternative social relationship types.

  View details for DOI 10.1016/j.gloepi.2023.100099

  View details for PubMedID 37638366

• Eleven years of student replication projects provide evidence on the correlates of replicability in psychology. Royal Society open science Boyce, V., Mathur, M., Frank, M. C. 2023; 10 (11): 231240

  Abstract

  Cumulative scientific progress requires empirical results that are robust enough to support theory construction and extension. Yet in psychology, some prominent findings have failed to replicate, and large-scale studies suggest replicability issues are widespread. The identification of predictors of replication success is limited by the difficulty of conducting large samples of independent replication experiments, however: most investigations reanalyse the same set of 170 replications. We introduce a new dataset of 176 replications from students in a graduate-level methods course. Replication results were judged to be successful in 49% of replications; of the 136 where effect sizes could be numerically compared, 46% had point estimates within the prediction interval of the original outcome (versus the expected 95%). Larger original effect sizes and within-participants designs were especially related to replication success. Our results indicate that, consistent with prior reports, the robustness of the psychology literature is low enough to limit cumulative progress by student investigators.

  View details for DOI 10.1098/rsos.231240

  View details for PubMedID 38026006

  View details for PubMedCentralID PMC10645069

• Effects of an educational planetary plate graphic on meat consumption in aStanford University dining hall: a randomized controlled trial. BMC nutrition Marcone, A. L., Darmstadt, G. L., Challamel, G. A., Mathur, M. B., Gardner, C. D. 2023; 9 (1): 106

  Abstract

  BACKGROUND: Assess the impact of an educational Planetary Health Plate (PHP) graphic on meat-related dietary choices of Stanford University dining hall patrons using a randomized controlled trial crossover design. All patrons entering the dining hall during study periods were enrolled as participants. Control, n=631; PHP, n=547.METHODS: Compare dietary behavior without signage to behavior while exposed to PHP during four equivalent dinner meals. The primary outcome was total meat-dish weight adjusted for the number of people entering the dining hall. Secondary outcomes included the number of meat-dish servings and average meat-dish serving weight. Analysis using T-tests, Poisson generalized linear model.RESULTS: Differences in total meat-dish weight, (1.54kg; 95% Confidence Interval [CI]=-4.41,1.33; P=.19) and average meat-dish serving weight (0.03kg; 95% CI=0.00, 0.06; P=.07) between PHP and control patrons did not reach significance. The rate at which PHP patrons took meat was significantly lower (Incidence Rate Ratio 0.80; 95% CI=0.71, 0.91; P<.001).CONCLUSION: Exposure to an educational plate graphic decreased the proportion of patrons taking meat but had no impact on total meat consumption or meat-dish serving weight. Statistical methods used in this study may inform future investigations on dietary change in the dining hall setting. Further research on the role of educational signage in influencing dietary behavior is warranted, with an aim to improve human health and environmental sustainability.TRIAL REGISTRATION: ClinicalTrials.gov, NCT05565859, registered 4 October 2022.

  View details for DOI 10.1186/s40795-023-00764-3

  View details for PubMedID 37749609

• Sensitivity analysis for the interactive effects of internal bias and publication bias in meta-analyses RESEARCH SYNTHESIS METHODS Mathur, M. B. 2024; 15 (1): 21-43

  Abstract

  Meta-analyses can be compromised by studies' internal biases (e.g., confounding in nonrandomized studies) as well as publication bias. These biases often operate nonadditively: publication bias that favors significant, positive results selects indirectly for studies with more internal bias. We propose sensitivity analyses that address two questions: (1) "For a given severity of internal bias across studies and of publication bias, how much could the results change?"; and (2) "For a given severity of publication bias, how severe would internal bias have to be, hypothetically, to attenuate the results to the null or by a given amount?" These methods consider the average internal bias across studies, obviating specifying the bias in each study individually. The analyst can assume that internal bias affects all studies, or alternatively that it only affects a known subset (e.g., nonrandomized studies). The internal bias can be of unknown origin or, for certain types of bias in causal estimates, can be bounded analytically. The analyst can specify the severity of publication bias or, alternatively, consider a "worst-case" form of publication bias. Robust estimation methods accommodate non-normal effects, small meta-analyses, and clustered estimates. As we illustrate by re-analyzing published meta-analyses, the methods can provide insights that are not captured by simply considering each bias in turn. An R package implementing the methods is available (multibiasmeta).

  View details for DOI 10.1002/jrsm.1667

  View details for Web of Science ID 001070499600001

  View details for PubMedID 37743567

  View details for PubMedCentralID PMC11164126

• A Specific Carbohydrate Diet Virtual Teaching Kitchen Curriculum Promotes Knowledge and Confidence in Caregivers of Pediatric Patients with Inflammatory Bowel Disease. Nutrients Rivera, N., Nguyen, K., Kalami, V., Qin, F., Mathur, M. B., Blankenburg, R., Yeh, A. M. 2023; 15 (18)

  Abstract

  Diet-based approaches such as the Specific Carbohydrate Diet (SCD) have proposed health benefits for patients with Inflammatory Bowel Disease (IBD). Despite its potential effectiveness, patients and caregivers identified barriers towards implementing the SCD, and a majority expressed interest in formal education surrounding the SCD. This study aimed to determine the impact of a virtual teaching kitchen curriculum on caregivers' knowledge and perspectives on implementing the SCD. Inclusion criteria included pediatric patients with IBD aged 3-21 years and their caregivers. Participants should have fewer than 12 months of experience with the SCD or have no experience with the SCD but with an interest in learning it. Twenty-three caregivers took part in a 90-min virtual teaching kitchen curriculum and completed pre- and post-session surveys. Caregivers had statistically significant increases in total curriculum scores (p < 0.0001) as well as increases in all curricular elements post-curriculum teaching. Caregivers indicated that they plan to apply the newly acquired recipes and cooking concepts and appreciated the encouragement and support they received during the course. Curricular strengths identified included the innovative multimodal curriculum structure and professional and community support. IBD centers can use this pilot study to create or expand SCD and other nutritional curricula for the IBD community.

  View details for DOI 10.3390/nu15183999

  View details for PubMedID 37764781

  View details for PubMedCentralID PMC10537188

• Exogenous female sex steroid hormones and new-onset asthma in women: a matched case-control study BMC MEDICINE Zhang, G., Basna, R., Mathur, M. B., Lasser, C., Mincheva, R., Ekerljung, L., Wennergren, G., Radinger, M., Lundback, B., Kankaanranta, H., Nwaru, B. I. 2023; 21 (1): 337

  Abstract

  Evidence on the role of exogenous female sex steroid hormones in asthma development in women remains conflicting. We sought to quantify the potential causal role of hormonal contraceptives and menopausal hormone therapy (MHT) in the development of asthma in women.We conducted a matched case-control study based on the West Sweden Asthma Study, nested in a representative cohort of 15,003 women aged 16-75 years, with 8-year follow-up (2008-2016). Data were analyzed using Frequentist and Bayesian conditional logistic regression models.We included 114 cases and 717 controls. In Frequentist analysis, the odds ratio (OR) for new-onset asthma with ever use of hormonal contraceptives was 2.13 (95% confidence interval [CI] 1.03-4.38). Subgroup analyses showed that the OR increased consistently with older baseline age. The OR for new-onset asthma with ever MHT use among menopausal women was 1.17 (95% CI 0.49-2.82). In Bayesian analysis, the ORs for ever use of hormonal contraceptives and MHT were, respectively, 1.11 (95% posterior interval [PI] 0.79-1.55) and 1.18 (95% PI 0.92-1.52). The respective probability of each OR being larger than 1 was 72.3% and 90.6%.Although use of hormonal contraceptives was associated with an increased risk of asthma, this may be explained by selection of women by baseline asthma status, given the upward trend in the effect estimate with older age. This indicates that use of hormonal contraceptives may in fact decrease asthma risk in women. Use of MHT may increase asthma risk in menopausal women.

  View details for DOI 10.1186/s12916-023-03038-8

  View details for Web of Science ID 001063237800001

  View details for PubMedID 37667254

  View details for PubMedCentralID PMC10478448

• Effect Measure Modification by Covariates in Mediation: Extending Regression-based Causal Mediation Analysis. Epidemiology (Cambridge, Mass.) Li, Y., Mathur, M. B., Solomon, D. H., Ridker, P. M., Glynn, R. J., Yoshida, K. 2023; 34 (5): 661-672

  Abstract

  Existing methods for regression-based mediation analysis assume that the exposure-mediator effect, exposure-outcome effect, and mediator-outcome effect are constant across levels of the baseline characteristics of patients. However, investigators often have insight into how these underlying effects may be modified by baseline characteristics and are interested in how the resulting mediation effects, such as the natural direct effect (NDE), the natural indirect effect. (NIE), and the proportion mediated, are modified by these baseline characteristics. Motivated by an empirical example of anti-interleukin-1 therapy's benefit on incident anemia reduction and its mediation by an early change in an inflammatory biomarker, we extended the closed-form regression-based causal mediation analysis with effect measure modification (EMM). Using a simulated numerical example, we demonstrated that naive analysis without considering EMM can give biased estimates of NDE and NIE and visually illustrated how baseline characteristics affect the presence and magnitude of EMM of NDE and NIE. We then applied the extended method to the empirical example informed by pathophysiologic insights into potential EMM by age, diabetes, and baseline inflammation. We found that the proportion modified through the early post-treatment inflammatory biomarker was greater for younger, nondiabetic patients with lower baseline level of inflammation, suggesting differential usefulness of the early post-treatment inflammatory biomarker in monitoring patients depending on baseline characteristics. To facilitate the adoption of EMM considerations in causal mediation analysis by the wider clinical and epidemiologic research communities, we developed a free- and open-source R package, regmedint.

  View details for DOI 10.1097/EDE.0000000000001643

  View details for PubMedID 37527449

• A Social Media-Based Public Health Campaign to Reduce Indoor Tanning in High-Risk Populations. AJPM focus de Vere Hunt, I., Cai, Z. R., Nava, V., Admassu, N. E., Bousheri, S., Johnson, T., Tomz, A., Thompson, J., Zhang, L., Pagoto, S., Wehner, M. R., Mathur, M. B., Linos, E. 2023; 2 (3): None

  Abstract

  Indoor tanning beds cause more than 450,000 new skin cancers each year, yet their use remains common, with a global indoor tanning prevalence of 10.4%. Social media provides an opportunity for cost-effective, targeted public health messaging. We sought to direct Instagram users at high risk of indoor tanning to accurate health information about the risks of indoor tanning and to reduce indoor tanning bed use.We disseminated a public health campaign on Instagram on April 6-27, 2022 with 34 video and still-image advertisements. We had 2 target audiences at high risk of indoor tanning: women aged 18-30 years in Kentucky, Nebraska, Ohio, or Tennessee interested in indoor tanning and men aged 18-45 years in California interested in indoor tanning. To evaluate the impact of the campaign, we tracked online metrics, including website visits, and conducted an interrupted time-series analysis of foot traffic data in our target states for all tanning salons documented on SafeGraph from January 1, 2018 to 3 months after the campaign.Our indoor tanning health information advertisements appeared on Instagram feeds 9.1 million times, reaching 1.06 million individuals. We received 7,004 views of our indoor tanning health information landing page (Average Time on Page of 56 seconds). We did not identify a significant impact on foot traffic data on tanning salons.We show the successful use of social media advertising to direct high-risk groups to online health information about indoor tanning. Future research quantifying tanning visits before and after indoor tanning interventions is needed to guide future public health efforts.

  View details for DOI 10.1016/j.focus.2023.100123

  View details for PubMedID 37662553

  View details for PubMedCentralID PMC10465716

• Is There Evidence of P-Hacking in Imaging Research? CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Rooprai, P., Islam, N., Salameh, J., Ebrahimzadeh, S., Kazi, A., Frank, R., Ramsay, T., Mathur, M. B., Absi, M., Khalil, A., Kazi, S., Dawit, H., Lam, E., Fabiano, N., McInnes, M. F. 2023; 74 (3): 497-507

  Abstract

  P-hacking, the tendency to run selective analyses until they become significant, is prevalent in many scientific disciplines.This study aims to assess if p-hacking exists in imaging research.Protocol, data, and code available here https://osf.io/xz9ku/?view_only=a9f7c2d841684cb7a3616f567db273fa. We searched imaging journals Ovid MEDLINE from 1972 to 2021. Text mining using Python script was used to collect metadata: journal, publication year, title, abstract, and P-values from abstracts. One P-value was randomly sampled per abstract. We assessed for evidence of p-hacking using a p-curve, by evaluating for a concentration of P-values just below .05. We conducted a one-tailed binomial test (α = .05 level of significance) to assess whether there were more P-values falling in the upper range (e.g., .045 < P < .05) than in the lower range (e.g., .04 < P < .045). To assess variation in results introduced by our random sampling of a single P-value per abstract, we repeated the random sampling process 1000 times and pooled results across the samples. Analysis was done (divided into 10-year periods) to determine if p-hacking practices evolved over time.Our search of 136 journals identified 967,981 abstracts. Text mining identified 293,687 P-values, and a total of 4105 randomly sampled P-values were included in the p-hacking analysis. The number of journals and abstracts that were included in the analysis as a fraction and percentage of the total number was, respectively, 108/136 (80%) and 4105/967,981 (.4%). P-values did not concentrate just under .05; in fact, there were more P-values falling in the lower range (e.g., .04 < P < .045) than falling just below .05 (e.g., .045 < P < .05), indicating lack of evidence for p-hacking. Time trend analysis did not identify p-hacking in any of the five 10-year periods.We did not identify evidence of p-hacking in abstracts published in over 100 imaging journals since 1972. These analyses cannot detect all forms of p-hacking, and other forms of bias may exist in imaging research such as publication bias and selective outcome reporting.

  View details for DOI 10.1177/08465371221139418

  View details for Web of Science ID 001034724000009

  View details for PubMedID 36412994

  View details for PubMedCentralID PMC10338063

• New metrics for multiple testing with correlated outcomes FRONTIERS IN APPLIED MATHEMATICS AND STATISTICS Mathur, M. B., VanderWeele, T. J. 2023; 9

  View details for DOI 10.3389/fams.2023.1151314

  View details for Web of Science ID 000989029000001

• Primary Care Physicians' Perceptions of the Effects of Being Overweight on All-cause Mortality EPIDEMIOLOGY Mathur, M. B., Mathur, V. S. 2023; 34 (3): E19-E20

  View details for DOI 10.1097/EDE.0000000000001590

  View details for Web of Science ID 000968041900002

  View details for PubMedID 36727941

  View details for PubMedCentralID PMC10368371

• A Brief Primer on Conducting Regression-Based Causal Mediation Analysis PSYCHOLOGICAL TRAUMA-THEORY RESEARCH PRACTICE AND POLICY Li, Y., Yoshida, K., Kaufman, J. S., Mathur, M. B. 2023

  View details for DOI 10.1037/tra0001421

  View details for Web of Science ID 000922683900001

  View details for PubMedID 36701540

• Variation across analysts in statistical significance, yet consistently small effect sizes PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Mathur, M. B., Covington, C., VanderWeele, T. J. 2023; 120 (3): e2218957120

  View details for DOI 10.1073/pnas.2218957120

  View details for Web of Science ID 001015766400002

  View details for PubMedID 36623183

  View details for PubMedCentralID PMC9933094

• Toward Open and Reproducible Epidemiology AMERICAN JOURNAL OF EPIDEMIOLOGY Mathur, M. B., Fox, M. P. 2023; 192 (4): 658-664

  Abstract

  Starting in the 2010s, researchers in the experimental social sciences rapidly began to adopt increasingly open and reproducible scientific practices. These practices include publicly sharing deidentified data when possible, sharing analytical code, and preregistering study protocols. Empirical evidence from the social sciences suggests such practices are feasible, can improve analytical reproducibility, and can reduce selective reporting. In academic epidemiology, adoption of open-science practices has been slower than in the social sciences (with some notable exceptions, such as registering clinical trials). Epidemiologic studies are often large, complex, conceived after data have already been collected, and difficult to replicate directly by collecting new data. These characteristics make it especially important to ensure their integrity and analytical reproducibility. Open-science practices can also pay immediate dividends to researchers' own work by clarifying scientific reasoning and encouraging well-documented, organized workflows. We consider how established epidemiologists and early-career researchers alike can help midwife a culture of open science in epidemiology through their research practices, mentorship, and editorial activities.

  View details for DOI 10.1093/aje/kwad007

  View details for Web of Science ID 000933725900001

  View details for PubMedID 36627249

  View details for PubMedCentralID PMC10089067

• Commentary: Quantifying the impact of bias to inform quality assessments in systematic reviews: The case of perchloroethylene and Non-Hodgkin's lymphoma. Global epidemiology Fox, M. P., Mathur, M. B., Matthay, E. C. 2022; 4: 100090

  View details for DOI 10.1016/j.gloepi.2022.100090

  View details for PubMedID 37637019

• Plant-based default nudges effectively increase the sustainability of catered meals on college campuses: Three randomized controlled trials FRONTIERS IN SUSTAINABLE FOOD SYSTEMS Boronowsky, R. D., Zhang, A. W., Stecher, C., Presley, K., Mathur, M. B., Cleveland, D. A., Garnett, E., Wharton, C., Brown, D., Meier, A., Wang, M., Braverman, I., Jay, J. A. 2022; 6

  View details for DOI 10.3389/fsufs.2022.1001157

  View details for Web of Science ID 000887259200001

• Re. Assessing Uncontrolled Confounding in Associations of Being Overweight With All-Cause Mortality Response EPIDEMIOLOGY Mathur, M. B., VanderWeele, T. J. 2022; 33 (6): E22-E23

  View details for DOI 10.1097/EDE.0000000000001533

  View details for Web of Science ID 000865983200005

  View details for PubMedID 36220586

  View details for PubMedCentralID PMC9756971

• Using selection models to assess sensitivity to publication bias: A tutorial and call for more routine use CAMPBELL SYSTEMATIC REVIEWS Maier, M., VanderWeele, T. J., Mathur, M. B. 2022; 18 (3): e1256

  Abstract

  In meta-analyses, it is critical to assess the extent to which publication bias might have compromised the results. Classical methods based on the funnel plot, including Egger's test and Trim-and-Fill, have become the de facto default methods to do so, with a large majority of recent meta-analyses in top medical journals (85%) assessing for publication bias exclusively using these methods. However, these classical funnel plot methods have important limitations when used as the sole means of assessing publication bias: they essentially assume that the publication process favors large point estimates for small studies and does not affect the largest studies, and they can perform poorly when effects are heterogeneous. In light of these limitations, we recommend that meta-analyses routinely apply other publication bias methods in addition to or instead of classical funnel plot methods. To this end, we describe how to use and interpret selection models. These methods make the often more realistic assumption that publication bias favors "statistically significant" results, and the methods also directly accommodate effect heterogeneity. Selection models have been established for decades in the statistics literature and are supported by user-friendly software, yet remain rarely reported in many disciplines. We use a previously published meta-analysis to demonstrate that selection models can yield insights that extend beyond those provided by funnel plot methods, suggesting the importance of establishing more comprehensive reporting practices for publication bias assessment.

  View details for DOI 10.1002/cl2.1256

  View details for Web of Science ID 000819375400001

  View details for PubMedID 36909879

  View details for PubMedCentralID PMC9247867

• Patterns of tobacco use in low and middle income countries by tobacco product and sociodemographic characteristics: nationally representative survey data from 82 countries. BMJ (Clinical research ed.) Theilmann, M., Lemp, J. M., Winkler, V., Manne-Goehler, J., Marcus, M. E., Probst, C., Lopez-Arboleda, W. A., Ebert, C., Bommer, C., Mathur, M., Andall-Brereton, G., Bahendeka, S. K., Bovet, P., Farzadfar, F., Ghasemi, E., Mayige, M. T., Saeedi Moghaddam, S., Mwangi, K. J., Naderimagham, S., Sturua, L., Atun, R., Davies, J. I., Bärnighausen, T., Vollmer, S., Geldsetzer, P. 2022; 378: e067582

  Abstract

  To determine the prevalence and frequency of using any tobacco product and each of a detailed set of tobacco products, how tobacco use and frequency of use vary across countries, world regions, and World Bank country income groups, and the socioeconomic and demographic gradients of tobacco use and frequency of use within countries.Secondary analysis of nationally representative, cross-sectional, household survey data from 82 low and middle income countries collected between 1 January 2015 and 31 December 2020.Population based survey data.1 231 068 individuals aged 15 years and older.Self-reported current smoking, current daily smoking, current smokeless tobacco use, current daily smokeless tobacco use, pack years, and current use and use frequencies of each tobacco product. Products were any type of cigarette, manufactured cigarette, hand rolled cigarette, water pipe, cigar, oral snuff, nasal snuff, chewing tobacco, and betel nut (with and without tobacco).The smoking prevalence in the study sample was 16.5% (95% confidence interval 16.1% to 16.9%) and ranged from 1.1% (0.9% to 1.3%) in Ghana to 50.6% (45.2% to 56.1%) in Kiribati. The user prevalence of smokeless tobacco was 7.7% (7.5% to 8.0%) and prevalence was highest in Papua New Guinea (daily user prevalence of 65.4% (63.3% to 67.5%)). Although variation was wide between countries and by tobacco product, for many low and middle income countries, the highest prevalence and cigarette smoking frequency was reported in men, those with lower education, less household wealth, living in rural areas, and higher age.Both smoked and smokeless tobacco use and frequency of use vary widely across tobacco products in low and middle income countries. This study can inform the design and targeting of efforts to reduce tobacco use in low and middle income countries and serve as a benchmark for monitoring progress towards national and international goals.

  View details for DOI 10.1136/bmj-2021-067582

  View details for PubMedID 36041745

• Correction: Mathur et al. Effectiveness of a Theory-Informed Documentary to Reduce Consumption of Meat and Animal Products: Three Randomized Controlled Experiments. Nutrients 2021, 13, 4555. Nutrients Mathur, M. B., Peacock, J. R., Robinson, T. N., Gardner, C. D. 2022; 14 (13)

  Abstract

  The authors wish to make the following correction to this paper [...].

  View details for DOI 10.3390/nu14132672

  View details for PubMedID 35807960

• Interventions that influence animal-product consumption: A meta-review FUTURE FOODS Grundy, E. C., Slattery, P., Saeri, A. K., Watkins, K., Houlden, T., Farr, N., Askin, H., Lee, J., Mintoft-Jones, A., Cyna, S., Dziegielewski, A., Gelber, R., Rowe, A., Mathur, M. B., Timmons, S., Zhao, K., Wilks, M., Peacock, J. R., Harris, J., Rosenfeld, D. L., Bryant, C., Moss, D., Zorker, M. 2022; 5

  View details for DOI 10.1016/j.fufo.2021.100111

  View details for Web of Science ID 001097481400008

• The Effects of Exposure to Information About Animal Welfare Reforms on Animal Farming Opposition: A Randomized Experiment ANTHROZOOS Harris, J., Ladak, A., Mathur, M. B. 2022; 35 (6): 773-788

  View details for DOI 10.1080/08927936.2022.2062868

  View details for Web of Science ID 000787717200001

• E-values for effect heterogeneity and approximations for causal interaction INTERNATIONAL JOURNAL OF EPIDEMIOLOGY Mathur, M. B., Smith, L. H., Yoshida, K., Ding, P., VanderWeele, T. J. 2022; 51 (4): 1268-1275

  Abstract

  Estimates of effect heterogeneity (i.e. the extent to which the causal effect of one exposure varies across strata of a second exposure) can be biased if the exposure-outcome relationship is subject to uncontrolled confounding whose severity differs across strata of the second exposure.We propose methods, analogous to the E-value for total effects, that help to assess the sensitivity of effect heterogeneity estimates to possible uncontrolled confounding. These E-value analogues characterize the severity of uncontrolled confounding strengths that would be required, hypothetically, to 'explain away' an estimate of multiplicative or additive effect heterogeneity in the sense that appropriately controlling for those confounder(s) would have shifted the effect heterogeneity estimate to the null, or alternatively would have shifted its confidence interval to include the null. One can also consider shifting the estimate or confidence interval to an arbitrary non-null value. All of these E-values can be obtained using the R package EValue.We illustrate applying the proposed E-value analogues to studies on: (i) effect heterogeneity by sex of the effect of educational attainment on dementia incidence and (ii) effect heterogeneity by age on the effect of obesity on all-cause mortality.Reporting these proposed E-values could help characterize the robustness of effect heterogeneity estimates to potential uncontrolled confounding.

  View details for DOI 10.1093/ije/dyac073

  View details for Web of Science ID 000785786900001

  View details for PubMedID 35460421

  View details for PubMedCentralID PMC9365630

• Assessing Uncontrolled Confounding in Associations of Being Overweight With All-Cause Mortality JAMA NETWORK OPEN Mathur, M. B., VanderWeele, T. J. 2022; 5 (3): e222614

  Abstract

  This study investigates potential uncontrolled confounding in meta-analyses of the association of being overweight with all-cause mortality.

  View details for DOI 10.1001/jamanetworkopen.2022.2614

  View details for Web of Science ID 000777006000001

  View details for PubMedID 35344049

  View details for PubMedCentralID PMC8961316

• The puzzling relationship between multi-laboratory replications and meta-analyses of the published literature. Royal Society open science Lewis, M., Mathur, M. B., VanderWeele, T. J., Frank, M. C. 2022; 9 (2): 211499

  Abstract

  What is the best way to estimate the size of important effects? Should we aggregate across disparate findings using statistical meta-analysis, or instead run large, multi-laboratory replications (MLR)? A recent paper by Kvarven, Stromland and Johannesson (Kvarven et al. 2020 Nat. Hum. Behav. 4, 423-434. (doi:10.1038/s41562-019-0787-z)) compared effect size estimates derived from these two different methods for 15 different psychological phenomena. The authors reported that, for the same phenomenon, the meta-analytic estimate tended to be about three times larger than the MLR estimate. These results are a specific example of a broader question: What is the relationship between meta-analysis and MLR estimates? Kvarven et al. suggested that their results undermine the value of meta-analysis. By contrast, we argue that both meta-analysis and MLR are informative, and that the discrepancy between the two estimates that they observed is in fact still largely unexplained. Informed by re-analyses of Kvarven et al.'s data and by other empirical evidence, we discuss possible sources of this discrepancy and argue that understanding the relationship between estimates obtained from these two methods is an important puzzle for future meta-scientific research.

  View details for DOI 10.1098/rsos.211499

  View details for PubMedID 35223059

• How to report E-values for meta-analyses: Recommended improvements and additions to the new GRADE approach ENVIRONMENT INTERNATIONAL Mathur, M. B., VanderWeele, T. J. 2022; 160: 107032

  Abstract

  In a recent concept paper (Verbeek et al., 2021), the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group provides a preliminary proposal to improve its existing guidelines for assessing sensitivity to uncontrolled confounding in meta-analyses of nonrandomized studies. The new proposal centers on reporting the E-value for the meta-analytic mean and on comparing this E-value to a measured "reference confounder" to determine whether residual uncontrolled confounding in the meta-analyzed studies could or could not plausibly explain away the meta-analytic mean. Although we agree that E-value analogs for meta-analyses could be an informative addition to future GRADE guidelines, we suggest improvements to the Verbeek et al. (2021)'s specific proposal regarding: (1) their interpretation of comparisons between the E-value and the strengths of associations of a reference confounder; (2) their characterization of evidence strength in meta-analyses in terms of only the meta-analytic mean; and (3) the possibility of confounding bias that is heterogeneous across studies.

  View details for DOI 10.1016/j.envint.2021.107032

  View details for Web of Science ID 000760318800015

  View details for PubMedID 34954645

  View details for PubMedCentralID PMC8959014

• Effectiveness of a Theory-Informed Documentary to Reduce Consumption of Meat and Animal Products: Three Randomized Controlled Experiments. Nutrients Mathur, M. B., Peacock, J. R., Robinson, T. N., Gardner, C. D. 1800; 13 (12)

  Abstract

  Several societal issues could be mitigated by reducing global consumption of meat and animal products (MAP). In three randomized, controlled experiments (n=217 to 574), we evaluated the effects of a documentary that presents health, environmental, and animal welfare motivations for reducing MAP consumption. Study 1 assessed the documentary's effectiveness at reducing reported MAP consumption after 12 days. This study used methodological innovations to minimize social desirability bias, a widespread limitation of past research. Study 2 investigated discrepancies between the results of Study 1 and those of previous studies by further examining the role of social desirability bias. Study 3 assessed the documentary's effectiveness in a new population anticipated to be more responsive and upon enhancing the intervention content. We found that the documentary did not decrease reported MAP consumption when potential social desirability bias was minimized (Studies 1 and 3). The documentary also did not affect consumption among participants whose demographics suggested they might be more receptive (Study 3). However, the documentary did substantially increase intentions to reduce consumption, consistent with past studies (Studies 2 and 3). Overall, we conclude that some past studies of similar interventions may have overestimated effects due to methodological biases. Novel intervention strategies to reduce MAP consumption may be needed.

  View details for DOI 10.3390/nu13124555

  View details for PubMedID 34960107

• Multiple-bias Sensitivity Analysis Using Bounds EPIDEMIOLOGY Smith, L. H., Mathur, M. B., VanderWeele, T. J. 2021; 32 (5): 625-634

  Abstract

  Confounding, selection bias, and measurement error are well-known sources of bias in epidemiologic research. Methods for assessing these biases have their own limitations. Many quantitative sensitivity analysis approaches consider each type of bias individually, although more complex approaches are harder to implement or require numerous assumptions. By failing to consider multiple biases at once, researchers can underestimate-or overestimate-their joint impact. We show that it is possible to bound the total composite bias owing to these three sources and to use that bound to assess the sensitivity of a risk ratio to any combination of these biases. We derive bounds for the total composite bias under a variety of scenarios, providing researchers with tools to assess their total potential impact. We apply this technique to a study where unmeasured confounding and selection bias are both concerns and to another study in which possible differential exposure misclassification and confounding are concerns. The approach we describe, though conservative, is easier to implement and makes simpler assumptions than quantitative bias analysis. We provide R functions to aid implementation.

  View details for DOI 10.1097/EDE.0000000000001380

  View details for Web of Science ID 000680139400008

  View details for PubMedID 34224471

  View details for PubMedCentralID PMC9930160

• Religious Coping With Interpersonal Hurts: Psychosocial Correlates of the Brief RCOPE in Four Non-Western Countries PSYCHOLOGY OF RELIGION AND SPIRITUALITY Voytenko, V. L., Pargament, K., Cowden, R. G., Lemke, A. W., Kurniati, N., Bechara, A., Joynt, S., Tymchenko, S., Khalanskyi, V. V., Shtanko, L., Kocum, M., Korzhov, H., Mathur, M. B., Ho, M., VanderWeele, T. J., Worthington, E. L. 2023; 15 (1): 43-55

  View details for DOI 10.1037/rel0000441

  View details for Web of Science ID 000733141600001

• Meta-regression methods to characterize evidence strength using meaningful-effect percentages conditional on study characteristics RESEARCH SYNTHESIS METHODS Mathur, M. B., VanderWeele, T. J. 2021; 12 (6): 731-749

  Abstract

  Meta-regression analyses usually focus on estimating and testing differences in average effect sizes between individual levels of each meta-regression covariate in turn. These metrics are useful but have limitations: they consider each covariate individually, rather than in combination, and they characterize only the mean of a potentially heterogeneous distribution of effects. We propose additional metrics that address both limitations. Given a chosen threshold representing a meaningfully strong effect size, these metrics address the questions: "For a given joint level of the covariates, what percentage of the population effects are meaningfully strong?" and "For any two joint levels of the covariates, what is the difference between these percentages of meaningfully strong effects?" We provide semiparametric methods for estimation and inference and assess their performance in a simulation study. We apply the proposed methods to meta-regression analyses on memory consolidation and on dietary behavior interventions, illustrating how the methods can provide more information than standard reporting alone. To facilitate implementing the methods in practice, we provide reporting guidelines and simple R code.

  View details for DOI 10.1002/jrsm.1504

  View details for Web of Science ID 000689490200001

  View details for PubMedID 34196505

  View details for PubMedCentralID PMC8985876

• Estimating publication bias in meta-analyses of peer-reviewed studies: A meta-meta-analysis across disciplines and journal tiers RESEARCH SYNTHESIS METHODS Mathur, M. B., VanderWeele, T. J. 2021; 12 (2): 176-191

  Abstract

  Selective publication and reporting in individual papers compromise the scientific record, but are meta-analyses as compromised as their constituent studies? We systematically sampled 63 meta-analyses (each comprising at least 40 studies) in PLoS One, top medical journals, top psychology journals, and Metalab, an online, open-data database of developmental psychology meta-analyses. We empirically estimated publication bias in each, including only the peer-reviewed studies. Across all meta-analyses, we estimated that "statistically significant" results in the expected direction were only 1.17 times more likely to be published than "nonsignificant" results or those in the unexpected direction (95% CI: [0.93, 1.47]), with a confidence interval substantially overlapping the null. Comparable estimates were 0.83 for meta-analyses in PLoS One, 1.02 for top medical journals, 1.54 for top psychology journals, and 4.70 for Metalab. The severity of publication bias did differ across individual meta-analyses; in a small minority (10%; 95% CI: [2%, 21%]), publication bias appeared to favor "significant" results in the expected direction by more than threefold. We estimated that for 89% of meta-analyses, the amount of publication bias that would be required to attenuate the point estimate to the null exceeded the amount of publication bias estimated to be actually present in the vast majority of meta-analyses from the relevant scientific discipline (exceeding the 95th percentile of publication bias). Study-level measures ("statistical significance" with a point estimate in the expected direction and point estimate size) did not indicate more publication bias in higher-tier versus lower-tier journals, nor in the earliest studies published on a topic versus later studies. Overall, we conclude that the mere act of performing a meta-analysis with a large number of studies (at least 40) and that includes non-headline results may largely mitigate publication bias in meta-analyses, suggesting optimism about the validity of meta-analytic results.

  View details for DOI 10.1002/jrsm.1464

  View details for Web of Science ID 000589440300001

  View details for PubMedID 33108053

  View details for PubMedCentralID PMC7954980

• Infant Allergy Testing and Food Allergy Diagnoses Before and After Guidelines for Early Peanut Introduction. The journal of allergy and clinical immunology. In practice Lo, R. M., Purington, N., McGhee, S. A., Mathur, M. B., Shaw, G. M., Schroeder, A. R. 2020

  Abstract

  BACKGROUND: A landmark 2015 trial on early exposure to peanuts led to expert recommendations for screening and early peanut introduction in high-risk (severe eczema and/or egg allergy) infants, but the impact of this paradigm shift on allergy testing and diagnosis is unknown.OBJECTIVE: We assessed the effects of the Learning Early About Peanut Allergy (LEAP) trial and guideline publications on allergy testing and food allergy diagnoses in infants.METHODS: In this retrospective cohort study, de-identified administrative health claims from a commercial and Medicare advantage claims database were used. Infants with at least one year of continuous coverage were selected using newborn codes for birth hospitalizations from January 2010 to June 2018. Interrupted time series models were used to compare the prevalence of allergy testing before and after LEAP publication in February 2015 and formal guideline publication in January 2017.RESULTS: For 487,533 included infants, allergy testing increased after LEAP (risk ratio [RR]: 1.11 [95% CI, 1.07-1.15]) and guidelines (1.21 [1.18-1.23]). This increase of testing was also seen in infants not considered high-risk, both after LEAP (1.12 [1.08-1.17]) and guidelines (1.20 [1.16, 1.23]). For first-time allergy tests, post-guideline median number of allergens tested was 9 for serum tests and 10 for skin tests. Post-guidelines there was a significant increase in diagnosis of peanut (RR: 1.08 [1.00, 1.16]), egg (1.12 [1.05, 1.20]), and other food allergies (excluding milk) (1.22 [1.14, 1.31]).CONCLUSION: Allergy testing has increased, including in non-high-risk infants. Multi-allergen testing may be contributing to an increase in the diagnosis of other food allergies.

  View details for DOI 10.1016/j.jaip.2020.10.060

  View details for PubMedID 33186769

• Controversy and debate on credibility ceilings. Paper 1: Fundamental problems with the "credibility ceiling"method for meta-analyses JOURNAL OF CLINICAL EPIDEMIOLOGY Mathur, M. B., Vander Weele, T. J. 2020; 127: 208-210

  Abstract

  The "credibility ceiling" method was proposed to conduct sensitivity analysis for unmeasured confounding and other forms of bias in meta-analyses and has been used in umbrella reviews to grade evidence strength. However, we explain that the method has fundamental statistical flaws.We use statistical reasoning to assess the method's validity, providing intuition for our findings by presenting simple applied examples in which the method yields clearly incorrect conclusions.The credibility ceiling is not a valid bias correction, as we show mathematically and illustrate using examples in which, for example, the method incorrectly "adjusts" the meta-analytic point estimate in the wrong direction. Although the originators describe the method as limiting the credibility of any given observational study to a fixed ceiling, we show why this interpretation in fact bears little relation to what the method actually does.Given the fundamental problems with the credibility ceiling method and its demonstrated potential for misleading conclusions, we recommend against its use.

  View details for DOI 10.1016/j.jclinepi.2020.05.006

  View details for Web of Science ID 000589799000027

  View details for PubMedID 32450128

  View details for PubMedCentralID PMC8159013

• <i>E</i> Values and Incidence Density Sampling EPIDEMIOLOGY VanderWeele, T. J., Martin, J. N., Mathur, M. B. 2020; 31 (6): E51-E52

  View details for DOI 10.1097/EDE.0000000000001238

  View details for Web of Science ID 000577091900022

  View details for PubMedID 32769478

  View details for PubMedCentralID PMC10686704

• Controversy and debate on credibility ceilings. Paper 3: errors in the statistical justification for the "credibility ceiling"method remain uncorrected JOURNAL OF CLINICAL EPIDEMIOLOGY Mathur, M. B., Vander Weele, T. J. 2020; 127: 214-216

  Abstract

  We previously claimed that the credibility ceiling for meta-analyses is fundamentally flawed. We respond to Dr. Ioannidis' rebuttal of those claims.We use statistical reasoning.We agree with Dr. Ioannidis on some general points about the limitations of statistical sensitivity analyses. But critically, his response has entirely sidestepped responding to the crux of our argument, namely a direct mathematical demonstration that the method simply does not do what it was claimed to do. We reiterate that if our claim were false, it could be persuasively refuted if Dr. Ioannidis were to identify inaccuracies in our mathematical argument, which he has not done. Dr. Ioannidis had also dismissed as "absurd" the thought experiments we had used to illustrate the method's misleading conclusion; we explain why these examples still stand.Given that the crux of our argument remains unaddressed, we continue to recommend against use of the credibility ceiling method. We are, however, sympathetic to what seem to be the underlying aims of the method, if not the execution. Developing principled methods to address those aims would be useful.

  View details for DOI 10.1016/j.jclinepi.2020.05.002

  View details for Web of Science ID 000589799000029

  View details for PubMedID 32442482

  View details for PubMedCentralID PMC7988356

• Commentary: Developing best-practice guidelines for the reporting of E-values INTERNATIONAL JOURNAL OF EPIDEMIOLOGY VanderWeele, T. J., Mathur, M. B. 2020; 49 (5): 1495-1497

  View details for DOI 10.1093/ije/dyaa094

  View details for Web of Science ID 000606715400014

  View details for PubMedID 32743656

  View details for PubMedCentralID PMC7746396

• Assessing the impact of unmeasured confounders for credible and reliable real-world evidence. Pharmacoepidemiology and drug safety Zhang, X., Stamey, J. D., Mathur, M. B. 2020

  Abstract

  PURPOSE: We review statistical methods for assessing the possible impact of bias due to unmeasured confounding in real world data analysis and provide detailed recommendations for choosing among the methods.METHODS: By updating an earlier systematic review, we summarize modern statistical best practices for evaluating and correcting for potential bias due to unmeasured confounding in estimating causal treatment effect from non-interventional studies.RESULTS: We suggest a hierarchical structure for assessing unmeasured confounding. First, for initial sensitivity analyses, we strongly recommend applying a recently developed method, the E-value, that is straightforward to apply and does not require prior knowledge or assumptions about the unmeasured confounder(s). When some such knowledge is available, the E-value could be supplemented by the rule-out or array method at this step. If these initial analyses suggest results may not be robust to unmeasured confounding, subsequent analyses could be conducted using more specialized statistical methods, which we categorize based on whether they require access to external data on the suspected unmeasured confounder(s), internal data, or no data. Other factors for choosing the subsequent sensitivity analysis methods are also introduced and discussed, including the types of unmeasured confounders and whether the subsequent sensitivity analysis is intended to provide a corrected causal treatment effect.CONCLUSION: Various analytical methods have been proposed to address unmeasured confounding, but little research has discussed a structured approach to select appropriate methods in practice. In providing practical suggestions for choosing appropriate initial and, potentially, more specialized subsequent sensitivity analyses, we hope to facilitate the widespread reporting of such sensitivity analyses in non-interventional studies. The suggested approach also has the potential to inform pre-specification of sensitivity analyses before executing the analysis, and therefore increase the transparency and limit selective study reporting.

  View details for DOI 10.1002/pds.5117

  View details for PubMedID 32929830

• Many Labs 5: Registered Multisite Replication of the Tempting-Fate Effects in Risen and Gilovich (2008) ADVANCES IN METHODS AND PRACTICES IN PSYCHOLOGICAL SCIENCE Mathur, M. B., Bart-Plange, D., Aczel, B., Bernstein, M. H., Ciunci, A. M., Ebersole, C. R., Falcao, F., Ashbaugh, K., Hilliard, R. A., Jern, A., Kellier, D. J., Kessinger, G., Kolb, V. S., Kovacs, M., Lage, C., Langford, E., Lins, S., Manfredi, D., Meyet, V., Moore, D. A., Nave, G., Nunnally, C., Palinkas, A., Parks, K. P., Pessers, S., Ramos, T., Rudy, K., Salamon, J., Shubella, R. L., Silva, R., Steegen, S., Stein, L. R., Szaszi, B., Szecsi, P., Tuerlinckx, F., Vanpaemel, W., Vlachou, M., Wiggins, B. J., Zealley, D., Zrubka, M., Frank, M. C. 2020; 3 (3): 394-404

  View details for DOI 10.1177/2515245918785165

  View details for Web of Science ID 000707049600001

• Many Labs 5: Testing Pre-Data-Collection Peer Review as an Intervention to Increase Replicability ADVANCES IN METHODS AND PRACTICES IN PSYCHOLOGICAL SCIENCE Ebersole, C. R., Mathur, M. B., Baranski, E., Bart-Plange, D., Buttrick, N. R., Chartier, C. R., Corker, K. S., Corley, M., Hartshorne, J. K., IJzerman, H., Lazarevic, L. B., Rabagliati, H., Ropovik, I., Aczel, B., Aeschbach, L. F., Andrighetto, L., Arnal, J. D., Arrow, H., Babincak, P., Bakos, B. E., Banik, G., Baskin, E., Belopavlovic, R., Bernstein, M. H., Bialek, M., Bloxsom, N. G., Bodroza, B., Bonfiglio, D. B., Boucher, L., Bruehlmann, F., Brumbaugh, C. C., Casini, E., Chen, Y., Chiorri, C., Chopik, W. J., Christ, O., Ciunci, A. M., Claypool, H. M., Coary, S., Colic, M., Collins, W., Curran, P. G., Day, C. R., Dering, B., Dreber, A., Edlund, J. E., Falcao, F., Fedor, A., Feinberg, L., Ferguson, I. R., Ford, M., Frank, M. C., Fryberger, E., Garinther, A., Gawryluk, K., Ashbaugh, K., Giacomantonio, M., Giessner, S. R., Grahe, J. E., Guadagno, R. E., Halasa, E., Hancock, P. B., Hilliard, R. A., Hueffmeier, J., Hughes, S., Idzikowska, K., Inzlicht, M., Jern, A., Jimenez-Leal, W., Johannesson, M., Joy-Gaba, J. A., Kauff, M., Kellier, D. J., Kessinger, G., Kidwell, M. C., Kimbrough, A. M., King, J. J., Kolb, V. S., Kolodziej, S., Kovacs, M., Krasuska, K., Kraus, S., Krueger, L. E., Kuchno, K., Lage, C., Langford, E., Levitan, C. A., Souza de Lima, T., Lin, H., Lins, S., Loy, J. E., Manfredi, D., Markiewicz, L., Menon, M., Mercier, B., Metzger, M., Meyet, V., Millen, A. E., Miller, J. K., Montealegre, A., Moore, D. A., Muda, R., Nave, G., Nichols, A., Novak, S. A., Nunnally, C., Orlic, A., Palinkas, A., Panno, A., Parks, K. P., Pedovic, I., Pekala, E., Penner, M. R., Pessers, S., Petrovic, B., Pfeiffer, T., Pienkosz, D., Preti, E., Puric, D., Ramos, T., Ravid, J., Razza, T. S., Rentzsch, K., Richetin, J., Rife, S. C., Dalla Rosa, A., Rudy, K., Salamon, J., Saunders, B., Sawicki, P., Schmidt, K., Schuepfer, K., Schultze, T., Schulz-Hardt, S., Schuetz, A., Shabazian, A. N., Shubella, R. L., Siegel, A., Silva, R., Sioma, B., Skorb, L., Cunha de Souza, L., Steegen, S., Stein, L. R., Sternglanz, R., Stojilovic, D., Storage, D., Sullivan, G., Szaszi, B., Szecsi, P., Szoke, O., Szuts, A., Thomae, M., Tidwell, N. D., Tocco, C., Torka, A., Tuerlinckx, F., Vanpaemel, W., Vaughn, L., Vianello, M., Viganola, D., Vlachou, M., Walker, R. J., Weissgerber, S. C., Wichman, A. L., Wiggins, B. J., Wolf, D., Wood, M. J., Zealley, D., Zezelj, I., Zrubka, M., Nosek, B. A. 2020; 3 (3): 309-331

  View details for DOI 10.1177/2515245920958687

  View details for Web of Science ID 000707042400001

• Rejoinder: The Future of Outcome-Wide Studies STATISTICAL SCIENCE VanderWeele, T. J., Mathur, M. B., Chen, Y. 2020; 35 (3): 479-483

  View details for Web of Science ID 000568739100020

• New statistical metrics for multisite replication projects JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES A-STATISTICS IN SOCIETY Mathur, M. B., VanderWeele, T. J. 2020; 183 (3): 1145-1166

  View details for DOI 10.1111/rssa.12572

  View details for Web of Science ID 000534360700001

• How to Apply Multiple Imputation in Propensity Score Matching with Partially Observed Confounders: A Simulation Study and Practical Recommendations JOURNAL OF MODERN APPLIED STATISTICAL METHODS Ling, A., Montez-Rath, M., Mathur, M., Kapphahn, K., Desai, M. 2020; 19 (1)

  View details for DOI 10.22237/jmasm/1608552120

  View details for Web of Science ID 000664642500006

• Robust Metrics and Sensitivity Analyses for Meta-analyses of Heterogeneous Effects EPIDEMIOLOGY Mathur, M. B., VanderWeele, T. J. 2020; 31 (3): 356-358

  Abstract

  We recently suggested new statistical metrics for routine reporting in random-effects meta-analyses to convey evidence strength for scientifically meaningful effects under effect heterogeneity. First, given a chosen threshold of meaningful effect size, we suggested reporting the estimated proportion of true population effect sizes above this threshold. Second, we suggested reporting the proportion of effect sizes below a second, possibly symmetric, threshold in the opposite direction from the estimated mean. Our previous methods applied when the true population effects are approximately normal, when the number of studies is relatively large, and when the proportion is between approximately 0.15 and 0.85. Here, we additionally describe robust methods for point estimation and inference that perform well under considerably more general conditions, as we validate in an extensive simulation study. The methods are implemented in the R package MetaUtility (function prop_stronger). We describe application of the robust methods to conducting sensitivity analyses for unmeasured confounding in meta-analyses.

  View details for DOI 10.1097/EDE.0000000000001180

  View details for Web of Science ID 000528798000011

  View details for PubMedID 32141922

  View details for PubMedCentralID PMC7963111

• Evidence Relating Health Care Provider Burnout and Quality of Care ANNALS OF INTERNAL MEDICINE Mathur, M. B., VanderWeele, T. J. 2020; 172 (6): 437-438

  View details for DOI 10.7326/L19-0826

  View details for Web of Science ID 000520170800034

  View details for PubMedID 32176906

  View details for PubMedCentralID PMC7958380

• A Simple, Interpretable Conversion from Pearson's Correlation to Cohen's for <i>d</i> Continuous Exposures EPIDEMIOLOGY Mathur, M. B., VanderWeele, T. J. 2020; 31 (2): E16-E18

  View details for DOI 10.1097/EDE.0000000000001105

  View details for Web of Science ID 000532258500004

  View details for PubMedID 31688129

  View details for PubMedCentralID PMC7906439

• Uncanny but not confusing: Multisite study of perceptual category confusion in the Uncanny Valley COMPUTERS IN HUMAN BEHAVIOR Maya, M. B., Reichling, D. B., Lunardini, F., Geminiani, A., Antonietti, A., Ruijten, P. M., Levitan, C. A., Nave, G., Manfredi, D., Bessette-Symons, B., Szuts, A., Aczel, B. 2020; 103: 21-30

  View details for DOI 10.1016/j.chb.2019.08.029

  View details for Web of Science ID 000501411800003

• Reducing meat consumption by appealing to animal welfare: protocol for a meta-analysis and theoretical review. Systematic reviews Mathur, M. B., Robinson, T. N., Reichling, D. B., Gardner, C. D., Nadler, J., Bain, P. A., Peacock, J. 2020; 9 (1): 3

  Abstract

  BACKGROUND: Reducing meat consumption may improve human health, curb environmental damage and greenhouse gas emissions, and limit the large-scale suffering of animals raised in factory farms. Previous work has begun to develop interventions to reduce individual meat consumption, often by appealing directly to individual health motivations. However, research on nutritional behavior change suggests that interventions additionally linking behavior to ethical values, identity formation, and existing social movements may be particularly effective and longer-lasting. Regarding meat consumption, preliminary evidence and psychological theory suggest that appeals related to animal welfare may have considerable potential to effectively leverage these elements of human psychology. We aim to conduct a systematic review and quantitative meta-analysis evaluating the effectiveness of animal welfare-related appeals on actual or intended meat consumption or purchasing. Our investigation will critically synthesize the current state of knowledge regarding psychological mechanisms of intervening on individual meat consumption and empirically identify the psychological characteristics underlying the most effective animal welfare-based interventions.METHODS: We will systematically search eight academic databases and extensively search unpublished grey literature. We will include studies that assess interventions intended to reduce meat consumption or purchase through the mention or portrayal of animal welfare, that measure outcomes related to meat consumption or purchase, and that have a control condition. Eligible studies may recruit from any human population, be written in any language, and be published or released any time. We will meta-analyze the studies, reporting the pooled point estimate and additional metrics that describe the distribution of potentially heterogeneous effects. We will assess studies' risk of bias and conduct sensitivity analyses for publication bias. We describe possible follow-up analyses to investigate hypothesized moderators of intervention effectiveness.DISCUSSION: The findings of the proposed systematic review and meta-analysis, including any identified methodological limitations of the existing literature, could inform the design of successful evidence-based interventions with broad potential to improve human, animal, and environmental well-being.SYSTEMATIC REVIEW REGISTRATION: The protocol was preregistered via the Open Science Framework (https://osf.io/d3y56/registrations).

  View details for DOI 10.1186/s13643-019-1264-5

  View details for PubMedID 31907028

• Dialysis Initiation and All-Cause Mortality Among Incident Adult Patients With Advanced CKD: A Meta-analysis With Bias Analysis. Kidney medicine Fu, R. n., Sekercioglu, N. n., Mathur, M. B., Couban, R. n., Coyte, P. C. 2020; 3 (1): 64–75.e1

  Abstract

  Due to unmeasured confounding, observational studies have limitations when assessing whether dialysis initiation reduces mortality compared with conservative therapy among adults with advanced chronic kidney disease (CKD). We addressed this issue in this meta-analysis.Meta-analysis with bias analysis for unmeasured confounding.Adults with stage 4 or 5 CKD who had initiated dialysis or conservative treatment.Prospective or retrospective cohort studies comparing survival of dialysis versus conservatively managed patients were searched on MEDLINE and Embase from January 2009 to March 20, 2019.HRs of all-cause mortality associated with dialysis initiation compared with conservative treatment.We pooled HRs using a random-effects model. We estimated the percentage of effect sizes more protective than HRs of 0.80 and severity of unmeasured confounding that could reduce this percentage to only 10%. Subgroup analysis was performed for studies with only older patients (aged ≥ 65 years).12 studies were included that involved 16,609 dialysis patients and 3,691 conservatively managed patients. A random-effects model suggested that dialysis initiation was associated with a mean mortality HR of 0.47 (95% CI, 0.34-0.64), in which 92% (95% CI, 50%-100%) of the true effects were more protective than HRs of 0.80. To reduce the percentage of HRs < 0.80 to 10%, unmeasured confounder(s) would need to be associated with both dialysis initiation and mortality by relative risks of 4.05 (95% CI, 2.39-4.15), which is equivalent to shifting each study's estimated HR by 2.31-fold (95% CI, 1.51-2.36). Restricting studies to include only older patients did not modify the results.Limited number of studies and evidence on the absence of publication bias.Our findings suggest that dialysis initiation considerably reduces mortality among adults with advanced CKD. Future bias-adjusted meta-analyses need to assess outcomes beyond mortality.

  View details for DOI 10.1016/j.xkme.2020.09.013

  View details for PubMedID 33604540

  View details for PubMedCentralID PMC7873831

• Open-source software for mouse-tracking in Qualtrics to measure category competition BEHAVIOR RESEARCH METHODS Mathur, M. B., Reichling, D. B. 2019; 51 (5): 1987-1997

  Abstract

  Mouse-tracking is a sophisticated tool for measuring rapid, dynamic cognitive processes in real time, particularly in experiments investigating competition between perceptual or cognitive categories. We provide user-friendly, open-source software ( https://osf.io/st2ef/ ) for designing and analyzing such experiments online using the Qualtrics survey platform. The software consists of a Qualtrics template with embedded JavaScript and CSS along with R code to clean, parse, and analyze the data. No special programming skills are required to use this software. As we discuss, this software could be readily modified for use with other online survey platforms that allow the addition of custom JavaScript. We empirically validate the provided software by benchmarking its performance on previously tested stimuli (android robot faces) in a category-competition experiment with realistic crowdsourced data collection.

  View details for DOI 10.3758/s13428-019-01258-6

  View details for Web of Science ID 000490957800004

  View details for PubMedID 31197629

  View details for PubMedCentralID PMC6797645

• Challenges and Suggestions for Defining Replication "Success" When Effects May Be Heterogeneous: Comment on Hedges and Schauer (2019) PSYCHOLOGICAL METHODS Mathur, M. B., VanderWeele, T. J. 2019; 24 (5): 571-575

  Abstract

  Psychological scientists are now trying to replicate published research from scratch to confirm the findings. In an increasingly widespread replication study design, each of several collaborating sites (such as universities) independently tries to replicate an original study, and the results are synthesized across sites. Hedges and Schauer (2019) proposed statistical analyses for these replication projects; their analyses focus on assessing the extent to which results differ across the replication sites, by testing for heterogeneity among a set of replication studies, while excluding the original study. We agree with their premises regarding the limitations of existing analysis methods and regarding the importance of accounting for heterogeneity among the replications. This objective may be interesting in its own right. However, we argue that by focusing only on whether the replication studies have similar effect sizes to one another, these analyses are not particularly appropriate for assessing whether the replications in fact support the scientific effect under investigation or for assessing the power of multisite replication projects. We reanalyze Hedges and Schauer's (2019) example dataset using alternative metrics of replication success that directly address these objectives. We reach a more optimistic conclusion regarding replication success than they did, illustrating that the alternative metrics can lead to quite different conclusions from those of Hedges and Schauer (2019). (PsycINFO Database Record (c) 2019 APA, all rights reserved).

  View details for DOI 10.1037/met0000223

  View details for Web of Science ID 000488839300003

  View details for PubMedID 31580141

  View details for PubMedCentralID PMC6779319

• Media Portrayals and Public Health Implications for Suicide and Other Behaviors JAMA PSYCHIATRY VanderWeele, T. J., Mathur, M. B., Chen, Y. 2019; 76 (9): 891-892

  View details for DOI 10.1001/jamapsychiatry.2019.0842

  View details for Web of Science ID 000490563700006

  View details for PubMedID 31141100

• SOME DESIRABLE PROPERTIES OF THE BONFERRONI CORRECTION: IS THE BONFERRONI CORRECTION REALLY SO BAD? AMERICAN JOURNAL OF EPIDEMIOLOGY VanderWeele, T. J., Mathur, M. B. 2019; 188 (3): 617-618

  View details for DOI 10.1093/aje/kwy250

  View details for Web of Science ID 000467881700015

  View details for PubMedID 30452538

  View details for PubMedCentralID PMC6395159

• Missing data strategies for time-varying confounders in comparative effectiveness studies of non-missing time-varying exposures and right-censored outcomes. Statistics in medicine Desai, M. n., Montez-Rath, M. E., Kapphahn, K. n., Joyce, V. R., Mathur, M. B., Garcia, A. n., Purington, N. n., Owens, D. K. 2019

  Abstract

  The treatment of missing data in comparative effectiveness studies with right-censored outcomes and time-varying covariates is challenging because of the multilevel structure of the data. In particular, the performance of an accessible method like multiple imputation (MI) under an imputation model that ignores the multilevel structure is unknown and has not been compared to complete-case (CC) and single imputation methods that are most commonly applied in this context. Through an extensive simulation study, we compared statistical properties among CC analysis, last value carried forward, mean imputation, the use of missing indicators, and MI-based approaches with and without auxiliary variables under an extended Cox model when the interest lies in characterizing relationships between non-missing time-varying exposures and right-censored outcomes. MI demonstrated favorable properties under a moderate missing-at-random condition (absolute bias <0.1) and outperformed CC and single imputation methods, even when the MI method did not account for correlated observations in the imputation model. The performance of MI decreased with increasing complexity such as when the missing data mechanism involved the exposure of interest, but was still preferred over other methods considered and performed well in the presence of strong auxiliary variables. We recommend considering MI that ignores the multilevel structure in the imputation model when data are missing in a time-varying confounder, incorporating variables associated with missingness in the MI models as well as conducting sensitivity analyses across plausible assumptions.

  View details for DOI 10.1002/sim.8174

  View details for PubMedID 31099433

• Data availability, reusability, and analytic reproducibility: evaluating the impact of a mandatory open data policy at the journal Cognition ROYAL SOCIETY OPEN SCIENCE Hardwicke, T. E., Mathur, M. B., MacDonald, K., Nilsonne, G., Banks, G. C., Kidwell, M. C., Mohr, A., Clayton, E., Yoon, E. J., Tessler, M., Lenne, R. L., Altman, S., Long, B., Frank, M. C. 2018; 5 (8)

  View details for DOI 10.1098/rsos.180448

  View details for Web of Science ID 000443443000059

• Higher Absolute Lymphocyte Counts Predict Lower Mortality from Early-Stage Triple-Negative Breast Cancer CLINICAL CANCER RESEARCH Afghahi, A., Purington, N., Han, S. S., Desai, M., Pierson, E., Mathur, M. B., Seto, T., Thompson, C. A., Rigdon, J., Telli, M. L., Badve, S. S., Curtis, C. N., West, R. B., Horst, K., Gomez, S. L., Ford, J. M., Sledge, G. W., Kurian, A. W. 2018; 24 (12): 2851–58

  View details for DOI 10.1158/1078-0432.CCR-17-1323

  View details for Web of Science ID 000435462700016

• Higher Absolute Lymphocyte Counts Predict Lower Mortality from Early-Stage Triple-Negative Breast Cancer. Clinical cancer research : an official journal of the American Association for Cancer Research Afghahi, A. n., Purington, N. n., Han, S. S., Desai, M. n., Pierson, E. n., Mathur, M. B., Seto, T. n., Thompson, C. A., Rigdon, J. n., Telli, M. L., Badve, S. S., Curtis, C. n., West, R. B., Horst, K. n., Gomez, S. L., Ford, J. M., Sledge, G. W., Kurian, A. W. 2018

  Abstract

  Tumor-infiltrating lymphocytes (TILs) in pre-treatment biopsies are associated with improved survival in triple-negative breast cancer (TNBC). We investigated whether higher peripheral lymphocyte counts are associated with lower breast cancer-specific mortality (BCM) and overall mortality (OM) in TNBC.Data on treatments and diagnostic tests from electronic medical records of two healthcare systems were linked with demographic, clinical, pathologic, and mortality data from the California Cancer Registry. Multivariable regression models adjusted for age, race/ethnicity, socioeconomic status, cancer stage, grade, neoadjuvant/adjuvant chemotherapy use, radiotherapy use, and germline BRCA1/2 mutations were used to evaluate associations between absolute lymphocyte count (ALC), BCM and OM. For a subgroup with TILs data available, we explored the relationship between TILs and peripheral lymphocyte counts.1,463 Stage I-III TNBC patients were diagnosed from 2000-2014; 1113 (76%) received neoadjuvant/adjuvant chemotherapy within one year of diagnosis. Of 759 patients with available ALC data, 481 (63.4%) were ever lymphopenic (minimum ALC <1.0 K/μL). On multivariable analysis, higher minimum ALC, but not absolute neutrophil count, predicted lower OM (hazard ratio [HR]: 0.23, 95% confidence interval [CI]: 0.16-0.35) and BCM (HR: 0.19, CI: 0.11-0.34). Five-year probability of BCM was 15% for patients who were ever lymphopenic versus 4% for those who were not. An exploratory analysis (N=70) showed a significant association between TILs and higher peripheral lymphocyte counts during neoadjuvant chemotherapy.Higher peripheral lymphocyte counts predicted lower mortality from early-stage, potentially curable TNBC, suggesting that immune function may enhance the effectiveness of early TNBC treatment.

  View details for PubMedID 29581131

• R Function for Additive Interaction Measures EPIDEMIOLOGY Mathur, M. B., VanderWeele, T. J. 2018; 29 (1): e5-e6

  View details for DOI 10.1097/EDE.0000000000000752

  View details for Web of Science ID 000417683700002

  View details for PubMedID 28901974

  View details for PubMedCentralID PMC5718923

• Guidelines for Generating Right-Censored Outcomes from a Cox Model Extended to Accommodate Time-Varying Covariates JOURNAL OF MODERN APPLIED STATISTICAL METHODS Montez-Rath, M. E., Kapphahn, K., Mathur, M. B., Mitani, A. A., Hendry, D. J., Desai, M. 2017; 16 (1): 86–106

  View details for DOI 10.22237/jmasm/1493597100

  View details for Web of Science ID 000411571000007

• Effect of a mobile app intervention on vegetable consumption in overweight adults: a randomized controlled trial. The international journal of behavioral nutrition and physical activity Mummah, S. n., Robinson, T. N., Mathur, M. n., Farzinkhou, S. n., Sutton, S. n., Gardner, C. D. 2017; 14 (1): 125

  Abstract

  Mobile applications (apps) have been heralded as transformative tools to deliver behavioral health interventions at scale, but few have been tested in rigorous randomized controlled trials. We tested the effect of a mobile app to increase vegetable consumption among overweight adults attempting weight loss maintenance.Overweight adults (n=135) aged 18-50 years with BMI=28-40 kg/m(2) near Stanford, CA were recruited from an ongoing 12-month weight loss trial (parent trial) and randomly assigned to either the stand-alone, theory-based Vegethon mobile app (enabling goal setting, self-monitoring, and feedback and using "process motivators" including fun, surprise, choice, control, social comparison, and competition) or a wait-listed control condition. The primary outcome was daily vegetables servings, measured by an adapted Harvard food frequency questionnaire (FFQ) 8 weeks post-randomization. Daily vegetable servings from 24-hour dietary recalls, administered by trained, certified, and blinded interviewers 5 weeks post-randomization, was included as a secondary outcome. All analyses were conducted according to principles of intention-to-treat.Daily vegetable consumption was significantly greater in the intervention versus control condition for both measures (adjusted mean difference: 2.0 servings; 95% CI: 0.1, 3.8, p=0.04 for FFQ; and 1.0 servings; 95% CI: 0.2, 1.9; p=0.02 for 24-hour recalls). Baseline vegetable consumption was a significant moderator of intervention effects (p=0.002) in which effects increased as baseline consumption increased.These results demonstrate the efficacy of a mobile app to increase vegetable consumption among overweight adults. Theory-based mobile interventions may present a low-cost, scalable, and effective approach to improving dietary behaviors and preventing associated chronic diseases.ClinicalTrials.gov NCT01826591. Registered 27 March 2013.

  View details for PubMedID 28915825

  View details for PubMedCentralID PMC5603006

• Synergistic drug combinations from electronic health records and gene expression. Journal of the American Medical Informatics Association Low, Y. S., Daugherty, A. C., Schroeder, E. A., Chen, W., Seto, T., Weber, S., Lim, M., Hastie, T., Mathur, M., Desai, M., Farrington, C., Radin, A. A., Sirota, M., Kenkare, P., Thompson, C. A., Yu, P. P., Gomez, S. L., Sledge, G. W., Kurian, A. W., Shah, N. H. 2016

  Abstract

  Using electronic health records (EHRs) and biomolecular data, we sought to discover drug pairs with synergistic repurposing potential. EHRs provide real-world treatment and outcome patterns, while complementary biomolecular data, including disease-specific gene expression and drug-protein interactions, provide mechanistic understanding.We applied Group Lasso INTERaction NETwork (glinternet), an overlap group lasso penalty on a logistic regression model, with pairwise interactions to identify variables and interacting drug pairs associated with reduced 5-year mortality using EHRs of 9945 breast cancer patients. We identified differentially expressed genes from 14 case-control human breast cancer gene expression datasets and integrated them with drug-protein networks. Drugs in the network were scored according to their association with breast cancer individually or in pairs. Lastly, we determined whether synergistic drug pairs found in the EHRs were enriched among synergistic drug pairs from gene-expression data using a method similar to gene set enrichment analysis.From EHRs, we discovered 3 drug-class pairs associated with lower mortality: anti-inflammatories and hormone antagonists, anti-inflammatories and lipid modifiers, and lipid modifiers and obstructive airway drugs. The first 2 pairs were also enriched among pairs discovered using gene expression data and are supported by molecular interactions in drug-protein networks and preclinical and epidemiologic evidence.This is a proof-of-concept study demonstrating that a combination of complementary data sources, such as EHRs and gene expression, can corroborate discoveries and provide mechanistic insight into drug synergism for repurposing.

  View details for DOI 10.1093/jamia/ocw161

  View details for PubMedID 27940607

• Direct-to-Consumer Drug Advertisements Can Paradoxically Increase Intentions to Adopt Lifestyle Changes FRONTIERS IN PSYCHOLOGY Mathur, M. B., Gould, M., Khazeni, N. 2016; 7

  Abstract

  Background: Direct-to-consumer (DTC) prescription drug advertisements are thought to induce "boomerang effects," meaning they reduce the perceived effectiveness of a potential alternative option: non-pharmaceutical treatment via lifestyle change. Past research has observed such effects using artificially created, text-only advertisements that may not adequate capture the complex, conflicting portrayal of lifestyle change in real television advertisements. In other risk domains, individual "problem status" often moderates boomerang effects, such that subjects who currently engage in the risky behavior exhibit the strongest boomerang effects. Objectives: We aimed to assess whether priming with real DTC television advertisements elicited boomerang effects on perceptions of lifestyle change and whether these effects, if present, were moderated by individual problem status. Methods: We assembled a sample of real, previously aired DTC television advertisements in order to naturalistically capture the portrayal of lifestyle change in real advertisements. We randomized 819 adults in the United States recruited via Amazon Mechanical Turk to view or not view an advertisement for a prescription drug. We further randomized subjects to judge either lifestyle change or drugs on three measures: general effectiveness, disease severity for a hypothetical patient, and personal intention to use the intervention if diagnosed with the target health condition. Results: Advertisement exposure induced a statistically significant, but weak, boomerang effect on general effectiveness (p = 0.01, partial R(2) = 0.007) and did not affect disease severity score (p = 0.32, partial R(2) = 0.0009). Advertisement exposure elicited a reverse boomerang effect of similar effect size on personal intentions, such that advertisement-exposed subjects reported comparatively higher intentions to use lifestyle change relative to drugs (p = 0.006, partial R(2) = 0.008). Individual problem status did not significantly moderate these effects. Conclusion: In contrast to previous literature finding large boomerang effects using artificial advertisement stimuli, real television advertisements elicited only a weak boomerang effect on perceived effectiveness and elicited an unexpected reverse boomerang effect on personal intentions to use lifestyle change versus drugs. These findings may reflect real advertisements' induction of descriptive norms and self-efficacy; future research could address such possibilities by systematically manipulating advertisement content.

  View details for DOI 10.3389/fpsyg.2016.01533

  View details for Web of Science ID 000384611000002

  View details for PubMedID 27752251

  View details for PubMedCentralID PMC5045930

• Reduced risk of myocardial infarct and revascularization following coronary artery bypass grafting compared with percutaneous coronary intervention in patients with chronic kidney disease. Kidney international Charytan, D. M., Desai, M., Mathur, M., Stern, N. M., Brooks, M. M., Krzych, L. J., Schuler, G. C., Kaehler, J., Rodriguez-Granillo, A. M., Hueb, W., Reeves, B. C., Thiele, H., Rodriguez, A. E., Buszman, P. P., Buszman, P. E., Maurer, R., Winkelmayer, W. C. 2016; 90 (2): 411-421

  Abstract

  Coronary atherosclerotic disease is highly prevalent in chronic kidney disease (CKD). Although revascularization improves outcomes, procedural risks are increased in CKD, and unbiased data comparing coronary artery bypass grafting (CABG) and percutaneous intervention (PCI) in CKD are sparse. To compare outcomes of CABG and PCI in stage 3 to 5 CKD, we identified randomized trials comparing these procedures. Investigators were contacted to obtain individual, patient-level data. Ten of 27 trials meeting inclusion criteria provided data. These trials enrolled 3993 patients encompassing 526 patients with stage 3 to 5 CKD of whom 137 were stage 3b-5 CKD. Among individuals with stage 3 to 5 CKD, survival through 5 years was not different after CABG compared with PCI (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.67-1.46) or stage 3b-5 CKD (HR 1.29, CI 0.68-2.46). However, CKD modified the impact on survival free of myocardial infarction: it was not different between CABG and PCI for individuals with preserved kidney function (HR 0.97, CI 0.80-1.17), but was significantly lower after CABG in stage 3-5 CKD (HR 0.49, CI 0.29-0.82) and stage 3b-5 CKD (HR 0.23, CI 0.09-0.58). Repeat revascularization was reduced after CABG compared with PCI regardless, of baseline kidney function. Results were limited by unavailability of data from several trials and paucity of enrolled patients with stage 4-5 CKD. Thus, our patient-level meta-analysis of individuals with CKD randomized to CABG versus PCI suggests that CABG significantly reduces the risk of subsequent myocardial infarction and revascularization without affecting survival in these patients.

  View details for DOI 10.1016/j.kint.2016.03.033

  View details for PubMedID 27259368

  View details for PubMedCentralID PMC4947016

• Use of Gene Expression Profiling and Chemotherapy in Early-Stage Breast Cancer: A Study of Linked Electronic Medical Records, Cancer Registry Data, and Genomic Data Across Two Health Care Systems. Journal of oncology practice / American Society of Clinical Oncology Afghahi, A., Mathur, M., Thompson, C. A., Mitani, A., Rigdon, J., Desai, M., Yu, P. P., de Bruin, M. A., Seto, T., Olson, C., Kenkare, P., Gomez, S. L., Das, A. K., Luft, H. S., Sledge, G. W., Sing, A. P., Kurian, A. W. 2016; 12 (6): e697-709

  Abstract

  The 21-gene recurrence score (RS) identifies patients with breast cancer who derive little benefit from chemotherapy; it may reduce unwarranted variability in the use of chemotherapy. We tested whether the use of RS seems to guide chemotherapy receipt across different cancer care settings.We developed a retrospective cohort of patients with breast cancer by using electronic medical record data from Stanford University (hereafter University) and Palo Alto Medical Foundation (hereafter Community) linked with demographic and staging data from the California Cancer Registry and RS results from the testing laboratory (Genomic Health Inc., Redwood City, CA). Multivariable analysis was performed to identify predictors of RS and chemotherapy use.In all, 10,125 patients with breast cancer were diagnosed in the University or Community systems from 2005 to 2011; 2,418 (23.9%) met RS guidelines criteria, of whom 15.6% received RS. RS was less often used for patients with involved lymph nodes, higher tumor grade, and age < 40 or ≥ 65 years. Among RS recipients, chemotherapy receipt was associated with a higher score (intermediate v low: odds ratio, 3.66; 95% CI, 1.94 to 6.91). A total of 293 patients (10.6%) received care in both health care systems (hereafter dual use); although receipt of RS was associated with dual use (v University: odds ratio, 1.73; 95% CI, 1.18 to 2.55), there was no difference in use of chemotherapy after RS by health care setting.Although there was greater use of RS for patients who sought care in more than one health care setting, use of chemotherapy followed RS guidance in University and Community health care systems. These results suggest that precision medicine may help optimize cancer treatment across health care settings.

  View details for DOI 10.1200/JOP.2015.009803

  View details for PubMedID 27221993

  View details for PubMedCentralID PMC4957259

• Higher peripheral lymphocyte count to predict survival in triple-negative breast cancer (TNBC). Afghahi, A., Rigdon, J., Purington, N., Desal, M., Pierson, E., Mathur, M., Thompson, C. A., Curtis, C., West, R. B., Horst, K. C., Gomez, S., Ford, J. M., Sledge, G. W., Kurian, A. W. AMER SOC CLINICAL ONCOLOGY. 2016

  View details for DOI 10.1200/JCO.2016.34.15_suppl.1010

  View details for Web of Science ID 000404665401132

• Perceived stress and telomere length: A systematic review, meta-analysis, and methodologic considerations for advancing the field. Brain, behavior, and immunity Mathur, M. B., Epel, E., Kind, S., Desai, M., Parks, C. G., Sandler, D. P., Khazeni, N. 2016; 54: 158-169

  Abstract

  Psychological stress contributes to numerous diseases and may do so in part through damage to telomeres, protective non-coding segments on the ends of chromosomes.We conducted a systematic review and meta-analysis to determine the association between self-reported, perceived psychological stress (PS) and telomere length (TL).We searched 3 databases (PubMed, PsycInfo, and Scopus), completed manual searches of published and unpublished studies, and contacted all study authors to obtain potentially relevant data.Two independent reviewers assessed studies for original research measuring (but not necessarily reporting the correlation between) PS and TL in human subjects. 23 studies met inclusion criteria; 22 (totaling 8948 subjects) could be meta-analyzed.We assessed study quality using modified MINORS criteria. Since not all included studies reported PS-TL correlations, we obtained them via direct calculation from author-provided data (7 studies), contact with authors (14 studies), or extraction from the published article (1 study).We conducted random-effects meta-analysis on our primary outcome, the age-adjusted PS-TL correlation. We investigated potential confounders and moderators (sex, life stress exposure, and PS measure validation) via post hoc subset analyses and meta-regression.Increased PS was associated with a very small decrease in TL (n=8724 total; r=-0.06; 95% CI: -0.10, -0.008; p=0.01; α=0.025), adjusting for age. This relationship was similar between sexes and within studies using validated measures of PS, and marginally (nonsignificantly) stronger among samples recruited for stress exposure (r=-0.13; vs. general samples: b=-0.11; 95% CI: -0.27, 0.01; p=0.05; α=0.013). Publication bias may exist; correcting for its effects attenuated the relationship.Our analysis finds a very small, statistically significant relationship between increased PS (as measured over the past month) and decreased TL that may reflect publication bias, although fully parsing the effects of publication bias from other sample-size correlates is challenging, as discussed. The association may be stronger with known major stressors and is similar in magnitude to that noted between obesity and TL. All included studies used single measures of short-term stress; the literature suggests long-term chronic stress may have a larger cumulative effect. Future research should assess for potential confounders and use longitudinal, multidimensional models of stress.

  View details for DOI 10.1016/j.bbi.2016.02.002

  View details for PubMedID 26853993

• Toward a mechanistic understanding of psychosocial factors in telomere degradation. Brain, behavior, and immunity Mathur, M. B., Epel, E., Kind, S., Desai, M., Parks, C. G., Sandler, D. P., Khazeni, N. 2016

  View details for DOI 10.1016/j.bbi.2016.04.011

  View details for PubMedID 27112382

• LACTATION AND FUTURE CARDIOVASCULAR DISEASE IN WOMEN: AN UNDER APPRECIATED TARGET FOR PREVENTION Rajaei, S., Tsai, S. A., Rigdon, J., Weber, S., Mathur, M., Tremmel, J. ELSEVIER SCIENCE INC. 2016: 1859

  View details for DOI 10.1016/S0735-1097(16)31860-5

  View details for Web of Science ID 000375188702705

• Mobile Technology for Vegetable Consumption: A Randomized Controlled Pilot Study in Overweight Adults. JMIR mHealth and uHealth Mummah, S. A., Mathur, M., King, A. C., Gardner, C. D., Sutton, S. 2016; 4 (2)

  Abstract

  Mobile apps present a potentially cost-effective tool for delivering behavior change interventions at scale, but no known studies have tested the efficacy of apps as a tool to specifically increase vegetable consumption among overweight adults.The purpose of this pilot study was to assess the initial efficacy and user acceptability of a theory-driven mobile app to increase vegetable consumption.A total of 17 overweight adults aged 42.0 (SD 7.3) years with a body mass index (BMI) of 32.0 (SD 3.5) kg/m(2) were randomized to the use of Vegethon (a fully automated theory-driven mobile app enabling self-monitoring of vegetable consumption, goal setting, feedback, and social comparison) or a wait-listed control condition. All participants were recruited from an ongoing 12-month weight loss trial (parent trial). Researchers who performed data analysis were blinded to condition assignment. The primary outcome measure was daily vegetable consumption, assessed using an adapted version of the validated Harvard Food Frequency Questionnaire administered at baseline and 12 weeks after randomization. An analysis of covariance was used to assess differences in 12-week vegetable consumption between intervention and control conditions, controlling for baseline. App usability and satisfaction were measured via a 21-item post-intervention questionnaire.Using intention-to-treat analyses, all enrolled participants (intervention: 8; control: 9) were analyzed. Of the 8 participants randomized to the intervention, 5 downloaded the app and logged their vegetable consumption a mean of 0.7 (SD 0.9) times per day, 2 downloaded the app but did not use it, and 1 never downloaded it. Consumption of vegetables was significantly greater among the intervention versus control condition at the end of the 12-week pilot study (adjusted mean difference: 7.4 servings; 95% CI 1.4-13.5; P=.02). Among secondary outcomes defined a priori, there was significantly greater consumption of green leafy vegetables, cruciferous vegetables, and dark yellow vegetables (adjusted mean difference: 2.6, 1.6, and 0.8 servings; 95% CI 0.1-5.0, 0.1-3.2, and 0.3-1.4; P=.04, P=.04, and P=.004, respectively). Participants reported positive experiences with the app, including strong agreement with the statements "I have found Vegethon easy to use" and "I would recommend Vegethon to a friend" (mean 4.6 (SD 0.6) and 4.2 (SD 0.8), respectively, (on a 5-point scale).Vegethon demonstrated initial efficacy and user acceptability. A mobile app intervention may be useful for increasing vegetable consumption among overweight adults. The small sample size prevented precise estimates of effect sizes. Given the improved health outcomes associated with increases in vegetable consumption, these findings indicate the need for larger, longer-term evaluations of Vegethon and similar technologies among overweight adults and other suitable target groups.ClinicalTrials.gov NCT01826591; https://clinicaltrials.gov/ct2/show/NCT01826591 (Archived by WebCite at http://www.webcitation.org/6hYDw2AOB).

  View details for DOI 10.2196/mhealth.5146

  View details for PubMedID 27193036

  View details for PubMedCentralID PMC4889871

• Navigating a social world with robot partners: A quantitative cartography of the Uncanny Valley COGNITION Mathur, M. B., Reichling, D. B. 2016; 146: 22-32

  Abstract

  Android robots are entering human social life. However, human-robot interactions may be complicated by a hypothetical Uncanny Valley (UV) in which imperfect human-likeness provokes dislike. Previous investigations using unnaturally blended images reported inconsistent UV effects. We demonstrate an UV in subjects' explicit ratings of likability for a large, objectively chosen sample of 80 real-world robot faces and a complementary controlled set of edited faces. An "investment game" showed that the UV penetrated even more deeply to influence subjects' implicit decisions concerning robots' social trustworthiness, and that these fundamental social decisions depend on subtle cues of facial expression that are also used to judge humans. Preliminary evidence suggests category confusion may occur in the UV but does not mediate the likability effect. These findings suggest that while classic elements of human social psychology govern human-robot social interaction, robust UV effects pose a formidable android-specific problem.

  View details for DOI 10.1016/j.cognition.2015.09.008

  View details for Web of Science ID 000367115500004

  View details for PubMedID 26402646

• Interactions Increase Forager Availability and Activity in Harvester Ants PLOS ONE Pless, E., Queirolo, J., Pinter-Wollman, N., Crow, S., Allen, K., Mathur, M. B., Gordon, D. M. 2015; 10 (11)

  Abstract

  Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  View details for DOI 10.1371/journal.pone.0141971

  View details for PubMedID 26539724

  View details for PubMedCentralID PMC4635008

• Lymphopenia after adjuvant radiotherapy (RT) to predict poor survival in triple-negative breast cancer (TNBC). Afghahi, A., Mathur, M., Seto, T., Desai, M., Kenkare, P., Horst, K. C., Das, A. K., Thompson, C. A., Luft, H. S., Yu, P., Gomez, S., Low, Y., Shah, N. H., Kurian, A. W., Sledge, G. W. AMER SOC CLINICAL ONCOLOGY. 2015

  View details for Web of Science ID 000358036900228

• SEX DIFFERENCES IN CORONARY PATHOPHYSIOLOGY IN PATIENTS WITH ANGINA IN THE ABSENCE OF OBSTRUCTIVE CORONARY ARTERY DISEASE Pargaonkar, V., Kobayashi, Y., Tanaka, S., Mathur, M. B., Nguyen, P., Lee, D., Fearon, W., Yeung, A., Tremmel, J. ELSEVIER SCIENCE INC. 2015: A1859

  View details for DOI 10.1016/S0735-1097(15)61859-9

  View details for Web of Science ID 000375328802181

• THE DIAGNOSTIC VALUE OF STRESS ECHOCARDIOGRAPHY AND ELECTROCARDIOGRAPHY IN IDENTIFYING OCCULT CORONARY ABNORMALITIES IN PATIENTS WITH ANGINA AND NO OBSTRUCTIVE CORONARY ARTERY DISEASE Pargaonkar, V., Khandelwal, A., Kobayashi, Y., Tanaka, S., Mathur, M. B., Froelicher, V., Yeung, A., Tremmel, J. ELSEVIER SCIENCE INC. 2015: A1623

  View details for DOI 10.1016/S0735-1097(15)61623-0

  View details for Web of Science ID 000375328801943

• Long-term prognosis of early repolarization with J-wave and QRS slur patterns on the resting electrocardiogram: a cohort study. Annals of internal medicine Pargaonkar, V. S., Perez, M. V., Jindal, A. n., Mathur, M. B., Myers, J. n., Froelicher, V. F. 2015; 163 (10): 747–55

  Abstract

  The prognostic value of early repolarization with J waves and QRS slurs remains controversial. Although these findings are more prevalent in patients with idiopathic ventricular fibrillation, their ability to predict cardiovascular death has varied across studies.To test the hypothesis that J waves and QRS slurs on electrocardiograms (ECGs) are associated with increased risk for cardiovascular death.Retrospective cohort.Veterans Affairs Palo Alto Health Care System.Veterans younger than 56 years who had resting 12-lead electrocardiography, 90.5% of whom were men.Electrocardiograms were manually measured and visually coded using criteria of 0.1 mV or greater in at least 2 contiguous leads. J waves were measured at the peak of an upward deflection or notch at the end of QRS, and QRS slurs were measured at the top of conduction delay on the QRS downstroke. Absolute risk differences at 10 years were calculated to study the associations between J waves or QRS slurs and the primary outcome of cardiovascular death.Over a median follow-up of 17.5 years, 859 cardiovascular deaths occurred. Of 20 661 ECGs, 4219 (20%) had J waves or QRS slurs in the inferior and/or lateral territories; of these, 3318 (78.6%) had J waves or QRS slurs in inferior leads and 1701 (40.3%) in lateral leads. The upper bound of differences in risk for cardiovascular death from any of the J-wave or QRS slur patterns suggests that an increased risk can be safely ruled out (inferior, -0.77% [95% CI, -1.27% to -0.27%]; lateral, -1.07% [CI, -1.72% to -0.43%]).The study consisted of predominantly men, and deaths could be classified as cardiovascular but not arrhythmic.J waves and QRS slurs did not exhibit a clinically meaningful increased risk for cardiovascular death in long-term follow-up.None.

  View details for DOI 10.7326/M15-0598

  View details for PubMedID 26501238

• Seasonal Patterns in Human A (H5N1) Virus Infection: Analysis of Global Cases PLOS ONE Mathur, M. B., Patel, R. B., Gould, M., Uyeki, T. M., Bhattacharya, J., Xiao, Y., Gillaspie, Y., Chae, C., Khazeni, N. 2014; 9 (9)

  Abstract

  Human cases of highly pathogenic avian influenza (HPAI) A (H5N1) have high mortality. Despite abundant data on seasonal patterns in influenza epidemics, it is unknown whether similar patterns exist for human HPAI H5N1 cases worldwide. Such knowledge could help decrease avian-to-human transmission through increased prevention and control activities during peak periods.We performed a systematic search of published human HPAI H5N1 cases to date, collecting month, year, country, season, hemisphere, and climate data. We used negative binomial regression to predict changes in case incidence as a function of season. To investigate hemisphere as a potential moderator, we used AIC and the likelihood-ratio test to compare the season-only model to nested models including a main effect or interaction with hemisphere. Finally, we visually assessed replication of seasonal patterns across climate groups based on the Köppen-Geiger climate classification.We identified 617 human cases (611 with complete seasonal data) occurring in 15 countries in Southeast Asia, Africa, and the Middle East. Case occurrence was much higher in winter (n = 285, p = 0.03) than summer (n = 64), and the winter peak occurred across diverse climate groups. There was no significant interaction between hemisphere and season.Across diverse climates, HPAI H5N1 virus infection in humans increases significantly in winter. This is consistent with increased poultry outbreaks and HPAI H5N1 virus transmission during cold and dry conditions. Prioritizing prevention and control activities among poultry and focusing public health messaging to reduce poultry exposures during winter months may help to reduce zoonotic transmission of HPAI H5N1 virus in resource-limited settings.

  View details for DOI 10.1371/journal.pone.0106171

  View details for Web of Science ID 000341774300008

  View details for PubMedCentralID PMC4162536

• Demographic and clinical predictors of mortality from highly pathogenic avian influenza A (H5N1) virus infection: CART analysis of international cases. PloS one Patel, R. B., Mathur, M. B., Gould, M., Uyeki, T. M., Bhattacharya, J., Xiao, Y., Khazeni, N. 2014; 9 (3)

  Abstract

  Human infections with highly pathogenic avian influenza (HPAI) A (H5N1) viruses have occurred in 15 countries, with high mortality to date. Determining risk factors for morbidity and mortality from HPAI H5N1 can inform preventive and therapeutic interventions.We included all cases of human HPAI H5N1 reported in World Health Organization Global Alert and Response updates and those identified through a systematic search of multiple databases (PubMed, Scopus, and Google Scholar), including articles in all languages. We abstracted predefined clinical and demographic predictors and mortality and used bivariate logistic regression analyses to examine the relationship of each candidate predictor with mortality. We developed and pruned a decision tree using nonparametric Classification and Regression Tree methods to create risk strata for mortality.We identified 617 human cases of HPAI H5N1 occurring between December 1997 and April 2013. The median age of subjects was 18 years (interquartile range 6-29 years) and 54% were female. HPAI H5N1 case-fatality proportion was 59%. The final decision tree for mortality included age, country, per capita government health expenditure, and delay from symptom onset to hospitalization, with an area under the receiver operator characteristic (ROC) curve of 0.81 (95% CI: 0.76-0.86).A model defined by four clinical and demographic predictors successfully estimated the probability of mortality from HPAI H5N1 illness. These parameters highlight the importance of early diagnosis and treatment and may enable early, targeted pharmaceutical therapy and supportive care for symptomatic patients with HPAI H5N1 virus infection.

  View details for DOI 10.1371/journal.pone.0091630

  View details for PubMedID 24667532

  View details for PubMedCentralID PMC3965392