Clinical Focus

  • Pediatric Infectious Diseases
  • Congenital Infections
  • Prenatal Screening for Congenital Infections with Point-of-Care Tests
  • Toxoplasmosis-Congenital Toxoplasmosis
  • Antimicrobial Stewardship
  • General Pediatrics
  • Antibiotics and Weight Gain
  • Outcomes Research
  • Methodology of Pediatric Clinical Research

Academic Appointments

Administrative Appointments

  • Affiliated Faculty of METRICS, Meta-Research Innovation Center at Stanford (METRICS) (2014 - Present)
  • Clinical Associate Professor, Clinician Educator Line, Stanford University School of Medicine, Dept of Pediatrics-Division of Infectious Diseases, Stanford, CA (2011 - Present)
  • Clinical Associate Professor, Clinician Educator Line, Stanford University School of Medicine, Dept of Medicine-Division of Infectious Diseases and Geographic Medicine, Stanford, CA (2010 - 2011)

Professional Education

  • Board Certification: American Board of Pediatrics, Pediatric Infectious Diseases (2021)
  • Certificate, American Board of Pediatrics-Subspecialty of Pediatric Infectious Diseases, Pediatric Infectious Diseases (2011)
  • Clinical and Research Fellowship, Children's National Medical Center and Center for Virology, Immunology and Infectious Disease, Children's Research Institute, George Washington Univ. Sch. of Med. and Health Sciences, Pediatric Infectious Diseases (1998)
  • Clinical and Research Fellowship, Boston City Hospital, Division of Pediatric Infectious Diseases, and Maxwell Finland Laboratory for Infectious Diseases, Boston University Sch of Med, Pediatric Infectious Diseases (1996)
  • Pediatric Residency (PGY2-PGY3), Boston City Hospital, Boston University School of Medicine, Boston, MA, Pediatrics (1995)
  • Pediatric Residency (PGY1), Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, Pediatrics (1993)
  • MD, University of Athens Medical School, Athens Greece, Medicine (1990)

Current Research and Scholarly Interests

Evidence based medicine, systematic reviews and meta-analysis
Congenital Infections
Congenital Toxoplasmosis
Point-Of-Care (POC) Tests for Congenital Infections: Validation of POC-tests for Toxoplasma Infections
Prenatal Screening for Congenital Infections using POC-tests
Guidelines Development for Congenital Infections
Improving Laboratory Diagnosis of Congenital Toxoplasmosis
Family outbreaks of acute toxoplasmosis in the US
Outcomes research (Patient safety)
Antimicrobial Stewardship
Early Life Antibiotic Use and Weight Gain: a 10 year retrospective cohort study
Comparative effectiveness and Comparative safety of medical interventions in diverse patient populations (adults vs children), settings (less developed countries vs. more developed countries) and study designs (RCTs vs routinely collected data)
Empirical appraisal of CEA for pediatric vaccines (with and without inclusion of herd immunity assumptions)
Empirical multidomain evaluation of the life cycle of translational research for medical interventions.

2021-22 Courses

All Publications

  • Large Pediatric Randomized Clinical Trials in Pediatrics Cho, S. M., Serghiou, S., Ioannidis, J. P., Klassen, T. P., Contopoulos-Ioannidis, D. G. 2021; 148 (3)


    BACKGROUND: Large, randomized controlled trials (RCTs) are essential in answering pivotal questions in child health.METHODS: We created a bird's eye view of all large, noncluster, nonvaccine pediatric RCTs with ≥1000 participants registered in (last search January 9, 2020). We analyzed the funding sources, countries, outcomes, publication status, and correlation with the pediatric global burden of disease (GBD) for eligible trials.RESULTS: We identified 247 large, nonvaccine, noncluster pediatric RCTs. Only 17 mega-trials with ≥5000 participants existed. Industry funding was involved in only 52 (21%) and exclusively funded 47 (19%) trials. Participants were from high-income countries (HICs) in 100 (40%) trials, from lower-middle-income countries (LMICs) in 122 (49%) trials, and from both HICs and LMICs in 19 (8%) trials; 6 trials did not report participants' country location. Of trials conducted in LMIC, 43% of investigators were from HICs. Of non-LMIC participants trials (HIC or HIC and LMIC), 39% were multicountry trials versus 11% of exclusively LMIC participants trials. Few trials (18%; 44 of 247) targeted mortality as an outcome. 35% (58 of 164) of the trials completed ≥12 months were unpublished at the time of our assessment. The number of trials per disease category correlated well with pediatric GBD overall (rho = 0.76) and in LMICs (rho = 0.69), but not in HICs (rho = 0.29).CONCLUSIONS: Incentivization of investigator collaborations across diverse country settings, timely publication of results of large pediatric RCTs, and alignment with the pediatric GBD are of pivotal importance to ultimately improve child health globally.

    View details for DOI 10.1542/peds.2020-049771

    View details for PubMedID 34465592

  • Late Diagnosis of Congenital Toxoplasmosis With Macrocephaly in Dizygotic Twins After Incidental Detection of Leukocoria: A Case Report. The Journal of pediatrics Del Valle Mojica, C., Montoya, J. G., McGuire, J., Palma, K. L., Shekdar, K. V., McLeod, R., Contopoulos-Ioannidis, D. G. 2021


    Untreated congenital toxoplasmosis remains an important cause of neurologic and ocular disease worldwide. However, congenitally infected infants may not have signs and symptoms their physicians recognize, leading to delayed diagnosis and missed opportunities for treatment. We describe a pair of twins diagnosed with congenital toxoplasmosis at 11 months of age following incidental detection of leukocoria in one twin.

    View details for DOI 10.1016/j.jpeds.2021.05.040

    View details for PubMedID 34023345

  • Toxoplasmosis in Pediatric Hematopoietic Stem Cell Transplantation Patients. Transplantation and cellular therapy Schwenk, H. T., Khan, A., Kohlman, K., Bertaina, A., Cho, S., Montoya, J. G., Contopoulos-Ioannidis, D. G. 2021; 27 (4): 292–300


    Infection due to the protozoa Toxoplasma gondii can be life-threatening in hematopoietic stem cell transplantation (HSCT) recipients. Most cases of toxoplasmosis in HSCT recipients result from reactivation of latent infection in individuals who were Toxoplasma-seropositive before transplantation and did not receive appropriate prophylaxis. Pretransplantation screening with Toxoplasma IgG and IgM antibodies is suggested for all allogeneic HSCT recipients and their donors and all autologous HSCT recipients. Prevention of toxoplasmosis in T. gondii-seropositive HSCT recipients requires primary prophylaxis, preemptive screening, or both. Trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred agent for Toxoplasma prophylaxis and should be continued for 6 months or until the patient is no longer receiving immunosuppression, whichever is longer, assuming that immune reconstitution has occurred. Preemptive weekly screening with whole blood Toxoplasma PCR should be considered for seropositive HSCT recipients if prophylaxis cannot be given or if prophylaxis other than TMP-SMX is used. The signs, symptoms, and radiographic findings of toxoplasmosis in HSCT recipients can be nonspecific, and the diagnosis requires a high degree of suspicion. Common presentations include fever, encephalopathy with mental status changes or seizures, and pneumonia. A Toxoplasma PCR analysis from whole blood (and other body fluids/tissues according to clinical symptoms) should be obtained in patients in whom there is a concern for toxoplasmosis. Treatment with oral pyrimethamine, sulfadiazine, and leucovorin for at least 6 weeks is the first-line therapy and should be followed by secondary prophylaxis. In this article, we review the published literature regarding the epidemiology, clinical presentation, treatment, and prevention of toxoplasmosis in HSCT recipients.

    View details for DOI 10.1016/j.jtct.2020.11.003

    View details for PubMedID 33840441

  • P value and Bayesian analysis in randomized-controlled trials in child health research published over 10 years, 2007 to 2017: a methodological review protocol. Systematic reviews Aregbesola, A., Gates, A., Coyle, A., Sim, S., Vandermeer, B., Skakum, M., Contopoulos-Ioannidis, D., Heath, A., Hartling, L., Klassen, T. P. 2021; 10 (1): 71


    BACKGROUND: There is an unresolved debate about the reliability of the interpretation of P value. Some investigators have suggested that an alternative Bayesian method is preferred in conducting health research. As randomized-controlled trials (RCTs) are important in generating research evidence, we decided to investigate the extent, if any, the inferential statistical framework in published RCTs in child health research have changed over 10 years. We aim to examine the change in P value and Bayesian analysis in RCTs in child health research papers published from 2007 to 2017.METHODS: We will search the Cochrane Central Register of Controlled Trials (Wiley) to identify relevant citations. We will leverage a pre-existing sample of child health RCTs published in 2007 (n=300) used in our previous study of reporting quality of pediatric RCTs. Using the same strategy and study selection methods, we will identify a comparable random sample of child health RCTs published in 2017 (n=300). Eligible studies will include RCTs in health research among individuals aged 21 years and below. One reviewer will select studies for inclusion and extract the data and another reviewer will verify these. Disagreements will be resolved by a discussion between reviewers or by involving another reviewer. We will perform a descriptive analysis of 2007 and 2017 samples and analyze the results using both the frequentist and Bayesian methods. We will present specific characteristics of the clinical trials from 2007 and 2017 in tabular and graphical forms. We will report the difference in the proportion of P value and Bayesian analysis between 2007 and 2017 to assess the 10-year change. Clustering around P values of significance, if observed, will be reported.DISCUSSION: This review will present the difference in the proportion of trials that reported on P value and Bayesian analysis between 2007 and 2017 to assess the 10-year change. The implications for future clinical research will be discussed and this research work will be published in a peer-reviewed journal. This review has the potential to help inform the need for a change in the methodological approach from the null hypothesis significance test to Bayesian methods.SYSTEMATIC REVIEW REGISTRATION: Open Science Framework

    View details for DOI 10.1186/s13643-021-01622-8

    View details for PubMedID 33691775

  • Response to Trimethoprim-Sulfamethoxazole in a Pediatric Hematopoietic Stem Cell Transplant Recipient With Disseminated Toxoplasmosis: A Case Report. Journal of the Pediatric Infectious Diseases Society Khan, A., Schwenk, H. T., Kohlman, K., Bertaina, A., Cho, S., Montoya, J. G., Contopoulos-Ioannidis, D. 2021


    We describe the presentation and treatment of a patient who developed ongoing fever and diagnosed with disseminated toxoplasmosis post-hematopoietic stem cell transplantation. He was initially treated with trimethoprim-sulfamethoxazole (TMP-SMX) and there was dramatic improvement in his fever curve. He successfully completed a modified course of therapy.

    View details for DOI 10.1093/jpids/piab006

    View details for PubMedID 33693793

  • Second versus first wave of COVID-19 deaths: shifts in age distribution and in nursing home fatalities. Environmental research Ioannidis, J. P., Axfors, C., Contopoulos-Ioannidis, D. G. 2021: 110856


    OBJECTIVE: To examine whether the age distribution of COVID-19 deaths and the share of deaths in nursing homes changed in the second versus the first pandemic wave.ELIGIBLE DATA: We considered all countries that had at least 4000 COVID-19 deaths occurring as of January 14, 2020, at least 200 COVID-19 deaths occurring in each of the two epidemic wave periods; and which had sufficiently detailed information available on the age distribution of these deaths. We also considered countries with data available on COVID-19 deaths of nursing home residents for the two waves.MAIN OUTCOME MEASURES: Change in the second wave versus the first wave in the proportion of COVID-19 deaths occurring in people <50 years ("young deaths") among all COVID-19 deaths and among COVID-19 deaths in people <70 years old; and change in the proportion of COVID-19 deaths in nursing home residents among all COVID-19 deaths.RESULTS: Data on age distribution were available for 14 eligible countries. Individuals <50 years old had small absolute difference in their share of the total COVID-19 deaths in the two waves across 13 high-income countries (absolute differences 0.0-0.4%). Their proportion was higher in Ukraine, but it decreased markedly in the second wave. The odds of young deaths was lower in the second versus the first wave (summary prevalence ratio 0.81, 95% CI 0.71-0.92) with large between-country heterogeneity. The odds of young deaths among deaths <70 years did not differ significantly across the two waves (summary prevalence ratio 0.96, 95% CI 0.86-1.06). Eligible data on nursing home COVID-19 deaths were available for 11 countries. The share of COVID-19 deaths that were accounted by nursing home residents decreased in the second wave significantly and substantially in 8 countries (prevalence ratio estimates: 0.36 to 0.78), remained the same in Denmark and Norway and markedly increased in Australia.CONCLUSIONS: In the examined countries, age distribution of COVID-19 deaths has been fairly similar in the second versus the first wave, but the contribution of COVID-19 deaths in nursing home residents to total fatalities has decreased in most countries in the second wave.

    View details for DOI 10.1016/j.envres.2021.110856

    View details for PubMedID 33581086

  • Toxoplasmosis Among 38,751 Hematopoietic Stem Cell Transplant Recipients: A Systematic Review of Disease Prevalence and a Compilation of Imaging and Autopsy Findings. Transplantation Contopoulos-Ioannidis, D. G., Cho, S. M., Bertaina, A., Leung, A. N., Fischbein, N., Lanzman, B., Schwenk, H. T., Montoya, J. G. 2021


    BACKGROUND: Toxoplasmosis in hematopoietic stem cell transplant-recipients (HSCT) can be life threatening if not promptly diagnosed and treated.METHODS: We performed a systematic review (PubMed last search 03/29/2020) of toxoplasmosis among HSCT-recipients and calculated the toxoplasmosis prevalence across studies. We also created a compilation list of brain imaging, chest imaging and autopsy findings of toxoplasmosis among HSCT-recipients.RESULTS: We identified 46 eligible studies (47 datasets) with 399 toxoplasmosis cases among 38751 HSCT-recipients. There was large heterogeneity in the reported toxoplasmosis prevalence across studies, thus formal meta-analysis was not attempted. The median toxoplasmosis prevalence among 38751 HSCT-recipients was 2.14% (range 0-66.67%). Data on toxoplasmosis among at-risk R+HSCT-recipients were more limited (25 studies; 2404 R+HSCT-recipients [6.2% of all HSCT-recipients]) although the median number of R+HSCT-recipients was 56.79% across all HSCT-recipients. Median toxoplasmosis prevalence across studies among 2404 R+HSCT was 7.51% (range 0-80%) vs 0% (range 0-1.23%) among 7438 R-HSCT. There were limited data to allow meaningful analyses of toxoplasmosis prevalence according to prophylaxis-status of R+HSCT-recipients.CONCLUSION: Toxoplasmosis prevalence among HSCT-recipients is underestimated. The majority of studies report toxoplasmosis prevalence among all HSCT-recipients rather than only among the at-risk R+HSCT-recipients. In fact, the median toxoplasmosis prevalence among all R+/R- HSCT-recipients is 3.5-fold lower compared to the prevalence among only the at-risk R+HSCT-recipients and the median prevalence among R+HSCT-recipients is 7.51-fold higher than among R-HSCT-recipients. The imaging findings of toxoplasmosis among HSCT-recipients can be atypical. High-index of suspicion is needed in R+HSCT-recipients with fever, pneumonia or encephalitis.

    View details for DOI 10.1097/TP.0000000000003662

    View details for PubMedID 33654004

  • Assessment of transparency indicators across the biomedical literature: How open is open? PLoS biology Serghiou, S. n., Contopoulos-Ioannidis, D. G., Boyack, K. W., Riedel, N. n., Wallach, J. D., Ioannidis, J. P. 2021; 19 (3): e3001107


    Recent concerns about the reproducibility of science have led to several calls for more open and transparent research practices and for the monitoring of potential improvements over time. However, with tens of thousands of new biomedical articles published per week, manually mapping and monitoring changes in transparency is unrealistic. We present an open-source, automated approach to identify 5 indicators of transparency (data sharing, code sharing, conflicts of interest disclosures, funding disclosures, and protocol registration) and apply it across the entire open access biomedical literature of 2.75 million articles on PubMed Central (PMC). Our results indicate remarkable improvements in some (e.g., conflict of interest [COI] disclosures and funding disclosures), but not other (e.g., protocol registration and code sharing) areas of transparency over time, and map transparency across fields of science, countries, journals, and publishers. This work has enabled the creation of a large, integrated, and openly available database to expedite further efforts to monitor, understand, and promote transparency and reproducibility in science.

    View details for DOI 10.1371/journal.pbio.3001107

    View details for PubMedID 33647013

  • Population-level COVID-19 mortality risk for non-elderly individuals overall and for non-elderly individuals without underlying diseases in pandemic epicenters. Environmental research Ioannidis, J. P., Axfors, C., Contopoulos-Ioannidis, D. G. 2020; 188: 109890


    OBJECTIVE: To provide estimates of the relative rate of COVID-19 death in people <65 years old versus older individuals in the general population, the absolute risk of COVID-19 death at the population level during the first epidemic wave, and the proportion of COVID-19 deaths in non-elderly people without underlying diseases in epicenters of the pandemic.ELIGIBLE DATA: Cross-sectional survey of countries and US states with at least 800 COVID-19 deaths as of April 24, 2020 and with information on the number of deaths in people with age <65. Data were available for 14 countries (Belgium, Canada, France, Germany, India, Ireland, Italy, Mexico, Netherlands, Portugal, Spain, Sweden, Switzerland, UK) and 13 US states (California, Connecticut, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Massachusetts, Michigan, New Jersey, New York, Pennsylvania). We also examined available data on COVID-19 deaths in people with age <65 and no underlying diseases.MAIN OUTCOME MEASURES: Proportion of COVID-19 deaths in people <65 years old; relative mortality rate of COVID-19 death in people <65 versus ≥65 years old; absolute risk of COVID-19 death in people <65 and in those ≥80 years old in the general population as of June 17, 2020; absolute COVID-19 mortality rate expressed as equivalent of mortality rate from driving a motor vehicle.RESULTS: Individuals with age <65 account for 4.5-11.2% of all COVID-19 deaths in European countries and Canada, 8.3-22.7% in the US locations, and were the majority in India and Mexico. People <65 years old had 30- to 100-fold lower risk of COVID-19 death than those ≥65 years old in 11 European countries and Canada, 16- to 52-fold lower risk in US locations, and less than 10-fold in India and Mexico. The absolute risk of COVID-19 death as of June 17, 2020 for people <65 years old in high-income countries ranged from 10 (Germany) to 349 per million (New Jersey) and it was 5 per million in India and 96 per million in Mexico. The absolute risk of COVID-19 death for people ≥80 years old ranged from 0.6 (Florida) to 17.5 per thousand (Connecticut). The COVID-19 mortality rate in people <65 years old during the period of fatalities from the epidemic was equivalent to the mortality rate from driving between 4 and 82 miles per day for 13 countries and 5 states, and was higher (equivalent to the mortality rate from driving 106-483 miles per day) for 8 other states and the UK. People <65 years old without underlying predisposing conditions accounted for only 0.7-3.6% of all COVID-19 deaths in France, Italy, Netherlands, Sweden, Georgia, and New York City and 17.7% in Mexico.CONCLUSIONS: People <65 years old have very small risks of COVID-19 death even in pandemic epicenters and deaths for people <65 years without underlying predisposing conditions are remarkably uncommon. Strategies focusing specifically on protecting high-risk elderly individuals should be considered in managing the pandemic.

    View details for DOI 10.1016/j.envres.2020.109890

    View details for PubMedID 32846654

  • The worldwide clinical trial research response to the COVID-19 pandemic - the first 100 days. F1000Research Janiaud, P., Axfors, C., Van't Hooft, J., Saccilotto, R., Agarwal, A., Appenzeller-Herzog, C., Contopoulos-Ioannidis, D. G., Danchev, V., Dirnagl, U., Ewald, H., Gartlehner, G., Goodman, S. N., Haber, N. A., Ioannidis, A. D., Ioannidis, J. P., Lythgoe, M. P., Ma, W., Macleod, M., Malicki, M., Meerpohl, J. J., Min, Y., Moher, D., Nagavci, B., Naudet, F., Pauli-Magnus, C., O'Sullivan, J. W., Riedel, N., Roth, J. A., Sauermann, M., Schandelmaier, S., Schmitt, A. M., Speich, B., Williamson, P. R., Hemkens, L. G. 2020; 9: 1193


    Background: Never before have clinical trials drawn as much public attention as those testing interventions for COVID-19. We aimed to describe the worldwide COVID-19 clinical research response and its evolution over the first 100 days of the pandemic. Methods: Descriptive analysis of planned, ongoing or completed trials by April 9, 2020 testing any intervention to treat or prevent COVID-19, systematically identified in trial registries, preprint servers, and literature databases. A survey was conducted of all trials to assess their recruitment status up to July 6, 2020. Results: Most of the 689 trials (overall target sample size 396,366) were small (median sample size 120; interquartile range [IQR] 60-300) but randomized (75.8%; n=522) and were often conducted in China (51.1%; n=352) or the USA (11%; n=76). 525 trials (76.2%) planned to include 155,571 hospitalized patients, and 25 (3.6%) planned to include 96,821 health-care workers. Treatments were evaluated in 607 trials (88.1%), frequently antivirals (n=144) or antimalarials (n=112); 78 trials (11.3%) focused on prevention, including 14 vaccine trials. No trial investigated social distancing. Interventions tested in 11 trials with >5,000 participants were also tested in 169 smaller trials (median sample size 273; IQR 90-700). Hydroxychloroquine alone was investigated in 110 trials. While 414 trials (60.0%) expected completion in 2020, only 35 trials (4.1%; 3,071 participants) were completed by July 6. Of 112 trials with detailed recruitment information, 55 had recruited <20% of the targeted sample; 27 between 20-50%; and 30 over 50% (median 14.8% [IQR 2.0-62.0%]). Conclusions: The size and speed of the COVID-19 clinical trials agenda is unprecedented. However, most trials were small investigating a small fraction of treatment options. The feasibility of this research agenda is questionable, and many trials may end in futility, wasting research resources. Much better coordination is needed to respond to global health threats.

    View details for DOI 10.12688/f1000research.26707.1

    View details for PubMedID 33082937

  • Reducing Piperacillin and Tazobactam Use for Pediatric Perforated Appendicitis. The Journal of surgical research Seddik, T. B., Rabsatt, L. A., Mueller, C. n., Bassett, H. K., Contopoulos-Ioannidis, D. n., Bio, L. L., Anderson, V. D., Schwenk, H. T. 2020; 260: 141–48


    Although perforated appendicitis is associated with infectious complications, the choice of antibiotic therapy is controversial. We assess the effectiveness and safety of an intervention to reduce piperacillin and tazobactam (PT) use for pediatric acute perforated appendicitis.This is a single-center, retrospective cohort study of children 18 y of age who underwent primary appendectomy for perforated appendicitis between January 01, 2016 and June 30, 2019. An intervention to decrease PT use was implemented: the first phase was provider education (April 19, 2017) and the second phase was modification of electronic antibiotic orders to default to ceftriaxone and metronidazole (July 06, 2017). Preintervention and postintervention PT exposure, use of PT ≥ half of intravenous antibiotic days, and clinical outcomes were compared.Forty children before and 109 after intervention were included and had similar baseline characteristics. PT exposure was 31 of 40 (78%) and 20 of 109 (18%) (P < 0.001), and use ≥ half of intravenous antibiotic days was 31 of 40 (78%) and 14 of 109 (13%) (P < 0.001), in the preintervention and postintervention groups, respectively. There was no significant difference in mean duration of antibiotic therapy (10.8 versus 9.8 d), mean length of stay (6.2 versus 6.5 d), rate of surgical site infection (10% versus 11%), or rate of 30-d readmission and emergency department visit (20% versus 20%) between the preintervention and postintervention periods, respectively.Provider education and modification of electronic antibiotic orders safely reduced the use of PT for pediatric perforated appendicitis.

    View details for DOI 10.1016/j.jss.2020.11.067

    View details for PubMedID 33340867

  • Congenital microcephaly hospitalizations in California infants: 1999-2013. Birth defects research Krasnow, M. R., Maldonado, Y. A., Contopoulos-Ioannidis, D. G. 2019


    INTRODUCTION: Population-level changes in microcephaly incidence risk (IR) could signal circulation of neurotropic pathogens or potential emerging teratogen exposure.METHODS: In this retrospective population cohort study, we estimated the IR of hospitalizations with a microcephaly ICD-9-CM discharge diagnosis code among infants ≤1 year over a 15-year period (1999-2013) using the Electronic Health Record (EHR) database from all hospital discharges in California from the Office of Statewide Hospital Planning and Development (OSHPD) database. We calculated the overall and yearly IRs per 10,000 live births (LBs) and per 10,000 hospitalizations in infants ≤1 year, and explored the impact in the IR estimates when children with microcephaly associated comorbidities were excluded or not.RESULTS: Among 8,860,153 hospital discharges of infants ≤1 year in the OSHPD database over this 15year period, we identified 6,004 hospitalizations with a microcephaly discharge diagnosis code; 3,526 of those were in neonates ≤30days. The IR of microcephaly hospitalizations for infants ≤1 year was 7.70/10,000 LB (for neonates it was 4.52/10,000 LB) and 6.78 per 10,000 hospitalizations ≤1 year. There was large heterogeneity in the yearly microcephaly IRs (I2 =66.6%).DISCUSSION: EHR collected data could be used as a complementary approach to track epidemiologic changes in microcephaly IRs. However, standardization in the use of microcephaly discharge diagnosis code and harmonization in the types of additional comorbidities to be excluded across analyses is mandatory to allow for prompt identification of true changes in microcephaly rates over time.

    View details for DOI 10.1002/bdr2.1604

    View details for PubMedID 31639287

  • Acute Toxoplasma infection in pregnant women worldwide: Asystematic review and meta-analysis. PLoS neglected tropical diseases Rostami, A., Riahi, S. M., Contopoulos-Ioannidis, D. G., Gamble, H. R., Fakhri, Y., Shiadeh, M. N., Foroutan, M., Behniafar, H., Taghipour, A., Maldonado, Y. A., Mokdad, A. H., Gasser, R. B. 2019; 13 (10): e0007807


    BACKGROUND: Acute Toxoplasma infection (ATI) during pregnancy, if left untreated, can cause severe adverse outcomes for the fetus and newborn. Here, we undertook a meta-analysis to estimate the worldwide prevalence of ATI in pregnant women.METHODS: We searched international databases for studies published between January 1988 and November 2018. We included population-based cross-sectional and prospective cohort studies that reported the prevalence of ATI in pregnant women. Data were synthesized using a random effect model to calculate the overall prevalence of ATI (with a 95% CI) in six WHO regions and globally. We also performed linear meta-regression analyses to investigate associations of maternal, socio-demographic, geographical and climate parameters with the prevalence of ATI.RESULTS: In total, 217 studies comprising 902,228 pregnant women across 74 countries were included in the meta-analysis. The overall prevalence of ATI in pregnant women globally was 1.1% (95% CI: 0.9-1.2%). In studies where more strict criteria for ATI were used, the overall prevalence was 0.6% (95% CI: 0.4-0.7%). The prevalence was highest in the Eastern Mediterranean region (2.5%; 95%CI: 1.7-3.4%) and lowest in the European region (0.5%; 95% CI: 0.4-0.7%). A significantly higher prevalence of ATI was found in countries with lower income levels (P = 0.027), lower human development indices (P = 0.04), higher temperatures (P = 0.02) and lower latitudes (P = 0.005) and longitudes (P = 0.02).CONCLUSIONS: The risk of acquiring ATI during gestation is clinically important and preventive measures to avoid exposure of pregnant women to Toxoplasma infection should be strictly applied.

    View details for DOI 10.1371/journal.pntd.0007807

    View details for PubMedID 31609966

  • Evaluation of Three Point-of-Care Tests for Detection of Toxoplasma Immunoglobulin IgG and IgM in the United States: Proof of Concept and Challenges OPEN FORUM INFECTIOUS DISEASES Gomez, C. A., Budvytyte, L. N., Press, C., Zhou, L., McLeod, R., Maldonado, Y., Montoya, J. G., Contopoulos-Ioannidis, D. G. 2018; 5 (10)
  • Rapid, inexpensive, fingerstick, whole-blood, sensitive, specific, point-of-care test for anti-Toxoplasma antibodies PLOS NEGLECTED TROPICAL DISEASES Lykins, J., Li, X., Levigne, P., Zhou, Y., El Bissati, K., Clouser, F., Wallon, M., Morel, F., Leahy, K., El Mansouri, B., Siddiqui, M., Leong, N., Michalowski, M., Irwin, E., Goodall, P., Ismail, M., Christmas, M., Adlaoui, E., Rhajaoui, M., Barkat, A., Cong, H., Begeman, I. J., Lai, B., Contopoulos-Ioannidis, D. G., Montoya, J. G., Maldonado, Y., Ramirez, R., Press, C., Peyron, F., McLeod, R. 2018; 12 (8): e0006536

    View details for PubMedID 30114251

  • Mother-to-child transmission of Chikungunya virus: A systematic review and meta-analysis PLOS NEGLECTED TROPICAL DISEASES Contopoulos-Ioannidis, D., Newman-Lindsay, S., Chow, C., LaBeaud, A. 2018; 12 (6)
  • Immunogenicity and safety of the multicomponent meningococcal B vaccine (4CMenB) in children and adolescents: a systematic review and meta-analysis LANCET INFECTIOUS DISEASES Flacco, M., Manzoli, L., Rosso, A., Marzuillo, C., Bergamini, M., Stefanati, A., Cultrera, R., Villari, P., Ricciardi, W., Ioannidis, J. A., Contopoulos-Ioannidis, D. G. 2018; 18 (4): 461–72


    The multicomponent meningococcal serogroup B vaccine (4CMenB) has been licensed in more than 35 countries. However, uncertainties remain about the lowest number of doses required to induce satisfactory, persistent immune responses. We did a systematic review and meta-analysis to provide quantitative estimates for the immunogenicity, persistence of immunogenicity, and safety of 4CMenB vaccine in children and adolescents.For this systematic review and meta-analyses (proportion, head to head, and network), we searched MEDLINE, Scopus, Embase, and from database inception to June 30, 2017, for randomised trials that compared the immunogenicity or safety of the 4CMenB vaccine with its originator meningococcal B recombinant vaccine or routine vaccines in children or adolescents. For proportion meta-analyses, we also included single arm trials and follow-up studies of randomised controlled trials. Trials that assessed immunogenicity against at least one of four Neisseria meningitidis serogroup B reference strains (44-76/SL, 5/99, NZ98/254, and M10713) and included participants younger than 18 years who had received two or more doses of the 4CMenB vaccine were eligible for inclusion. We requested individual patient-level data from study authors and extracted data from published reports and online trial registries. We did meta-analyses to assess 4CMenB safety and immunogenicity against the four reference strains 30 days after a primary immunisation course (three doses for children, two doses for adolescents), 30 days after the primary course plus one booster dose (children only), 6 months or more after primary course, and 6 months or more after the booster dose.736 non-duplicate records were screened, and ten randomised trials and eight follow-on extension trials on 4CMenB met the inclusion criteria. In intention-to-treat analyses, the overall proportion of children and adolescents who achieved seroconversion 30 days after the primary course of 4CMenB was 92% (95% CI 89-95 [I2=95%, p<0·0001]) for the 44/76-SL strain, 91% (87-95 [I2=95%, p<0·0001]) for the 5/99 strain, 84% (77-90 [I2=97%, p<0·0001]) for the NZ98-254 strain, and 87% (68-99 [I2=97%, p<0·0001]) for the M10713 strain. 6 months after the primary course, the immunogenicity remained adequate to high against all three tested strains (5/99, 44/76-SL, and NZ98/254) in adolescents (≥77%), and against two of four strains (5/99 and 44/76-SL) in children (≥67%): the proportion of patients who achieved seroconversion substantially declined for M10713 (<50%) and NZ98/254 (<35%). A booster dose re-enhanced the proportion of patients who achieved seroconversion (≥93% for all strains). However, immunogenicity remained high 6 months after the booster dose for strains 5/99 (95%) and M10713 (75%) only, whereas the proportion of patients who achieved seroconversion against strains 44/76-SL and NZ98/254 returned to similar proportions recorded 6 months after the primary course (62% for 44/76-SL, 35% for NZ98/254). The incidence of potentially vaccine-related, acute serious adverse events in individuals receiving 4CMenB was low (5·4 per 1000 individuals), but was significantly higher than routine vaccines (1·2 per 1000 individuals).4CMenB has an acceptable short-term safety profile. The primary course is sufficient to achieve a satisfactory immune response within 30 days of vaccination. A booster dose is required for children to prolong the protection against strain M10713, and the long-term immunogenicity against strain NZ98/254 remains suboptimal.None.

    View details for PubMedID 29371070

  • Comparative evidence on harms in pediatric randomized clinical trials from less developed versus more developed countries is limited JOURNAL OF CLINICAL EPIDEMIOLOGY Tedesco, D., Farid-Kapadia, M., Offringa, M., Bhutta, Z. A., Maldonado, Y., Ioannidis, J. A., Contopoulos-Ioannidis, D. G. 2018; 95: 63–72


    Evaluate comparative harm rates from medical interventions in pediatric randomized clinical trials (RCTs) from more developed (MDCs) and less developed countries (LDCs).Meta-epidemiologic empirical evaluation of Cochrane Database of Systematic Reviews (June 2014) meta-analyses reporting clinically important harm-outcomes (severe adverse events [AEs], discontinuations due to AEs, any AE, and mortality) that included at least one pediatric RCT from MDCs and at least one from LDCs. We estimated relative odds ratios (RORs) for each harm, within each meta-analysis, between RCTs from MDCs and LDCs and calculated random-effects-summary-RORs (sRORs) for each harm across multiple meta-analyses.Only 1% (26/2,363) of meta-analyses with clinically important harm-outcomes in the entire Cochrane Database of Systematic Reviews included pediatric RCTs both from MDCs and LDCs. We analyzed 26 meta-analyses with 244 data sets from pediatric RCTs, 116 from MDCs and 128 from LDCs (64 and 66 unique RCTs respectively). The summary ROR was 0.92 (95% confidence intervals: 0.78-1.08) for severe AEs; 1.13 (0.54-2.34) for discontinuations due to AEs; 1.10 (0.77-1.59) for any AE; and 0.99 (0.61-1.61) for mortality and for the all-harms-combined-end point 0.96 (0.83-1.10). Differences of ROR-point-estimates ≥2-fold between MDCs and LDCs were identified in 35% of meta-analyses.We found no major systematic differences in harm rates in pediatric trials between MDCs and LDCs, but data on harms in children were overall very limited.

    View details for PubMedID 29191447

  • The Conduct and Reporting of Child Health Research: An Analysis of Randomized Controlled Trials Published in 2012 and Evaluation of Change over 5 Years JOURNAL OF PEDIATRICS Gates, A., Hartling, L., Vandermeer, B., Caldwell, P., Contopoulos-Ioannidis, D. G., Curtis, S., Fernandes, R. M., Klassen, T. P., Williams, K., Dyson, M. P. 2018; 193: 237-+


    For child health randomized controlled trials (RCTs) published in 2012, we aimed to describe design and reporting characteristics and evaluate changes since 2007; assess the association between trial design and registration and risk of bias (RoB); and assess the association between RoB and effect size.For 300 RCTs, we extracted design and reporting characteristics and assessed RoB. We assessed 5-year changes in design and reporting (based on 300 RCTs we had previously analyzed) using the Fisher exact test. We tested for associations between design and reporting characteristics and overall RoB and registration using the Fisher exact, Cochran-Armitage, Kruskal-Wallis, and Jonckheere-Terpstra tests. We pooled effect sizes and tested for differences by RoB using the χ2 test for subgroups in meta-analysis.The 2012 and 2007 RCTs differed with respect to many design and reporting characteristics. From 2007 to 2012, RoB did not change for random sequence generation and improved for allocation concealment (P < .001). Fewer 2012 RCTs were rated high overall RoB and more were rated unclear (P = .03). Only 7.3% of 2012 RCTs were rated low overall RoB. Trial registration doubled from 2007 to 2012 (23% to 46%) (P < .001) and was associated with lower RoB (P = .009). Effect size did not differ by RoB (P = .43) CONCLUSIONS: Random sequence generation and allocation concealment were not often reported, and selective reporting was prevalent. Measures to increase trialists' awareness and application of existing reporting guidance, and the prospective registration of RCTs is needed to improve the trustworthiness of findings from this field.

    View details for PubMedID 29169611

  • Comparison of nuisance parameters in pediatric versus adult randomized trials: a meta-epidemiologic empirical evaluation BMC MEDICAL RESEARCH METHODOLOGY Vandermeer, B., van der Tweel, I., Jansen-van der Weide, M. C., Weinreich, S. S., Contopoulos-Ioannidis, D. G., Bassler, D., Fernandes, R. M., Askie, L., Saloojee, H., Baiardi, P., Ellenberg, S. S., van der Lee, J. H. 2018; 18: 7


    We wished to compare the nuisance parameters of pediatric vs. adult randomized-trials (RCTs) and determine if the latter can be used in sample size computations of the former.In this meta-epidemiologic empirical evaluation we examined meta-analyses from the Cochrane Database of Systematic-Reviews, with at least one pediatric-RCT and at least one adult-RCT. Within each meta-analysis of binary efficacy-outcomes, we calculated the pooled-control-group event-rate (CER) across separately all pediatric and adult-trials, using random-effect models and subsequently calculated the control-group event-rate risk-ratio (CER-RR) of the pooled-pediatric-CERs vs. adult-CERs. Within each meta-analysis with continuous outcomes we calculated the pooled-control-group effect standard deviation (CE-SD) across separately all pediatric and adult-trials and subsequently calculated the CE-SD-ratio of the pooled-pediatric-CE-SDs vs. adult-CE-SDs. We then calculated across all meta-analyses the pooled-CER-RRs and pooled-CE-SD-ratios (primary endpoints) and the pooled-magnitude of effect-sizes of CER-RRs and CE-SD-ratios using REMs. A ratio < 1 indicates that pediatric trials have smaller nuisance parameters than adult trials.We analyzed 208 meta-analyses (135 for binary-outcomes, 73 for continuous-outcomes). For binary outcomes, pediatric-RCTs had on average 10% smaller CERs than adult-RCTs (summary-CE-RR: 0.90; 95% CI: 0.83, 0.98). For mortality outcomes the summary-CE-RR was 0.48 (95% CIs: 0.31, 0.74). For continuous outcomes, pediatric-RCTs had on average 26% smaller CE-SDs than adult-RCTs (summary-CE-SD-ratio: 0.74).Clinically relevant differences in nuisance parameters between pediatric and adult trials were detected. These differences have implications for design of future studies. Extrapolation of nuisance parameters for sample-sizes calculations from adult-trials to pediatric-trials should be cautiously done.

    View details for PubMedID 29321002

  • Immunogenicity and safety of the multicomponent meningococcal B vaccine (4CMenB): a meta-analysis Flacco, M. E., Manzoli, L., Rosso, A., Marzuillo, C., Bergamini, M., Stefanati, A., Villari, P., Ricciardi, W., Ioannidis, J. P., Contopoulos-Ioannidis, D. G. OXFORD UNIV PRESS. 2017
  • Point-of-care testing for Toxoplasma gondii IgG/IgM using Toxoplasma ICT IgG-IgM test with sera from the United States and implications for developing countries PLOS NEGLECTED TROPICAL DISEASES Begeman, I. J., Lykins, J., Zhou, Y., Lai, B., Levigne, P., El Bissati, K., Boyer, K., Withers, S., Clouser, F., Noble, A., Rabiah, P., Swisher, C. N., Heydemann, P. T., Contopoulos-Ioannidis, D. G., Montoya, J. G., Maldonado, Y., Ramirez, R., Press, C., Stillwaggon, E., Peyron, F., McLeod, R. 2017; 11 (6): e0005670


    Congenital toxoplasmosis is a serious but preventable and treatable disease. Gestational screening facilitates early detection and treatment of primary acquisition. Thus, fetal infection can be promptly diagnosed and treated and outcomes can be improved.We tested 180 sera with the Toxoplasma ICT IgG-IgM point-of-care (POC) test. Sera were from 116 chronically infected persons (48 serotype II; 14 serotype I-III; 25 serotype I-IIIa; 28 serotype Atypical, haplogroup 12; 1 not typed). These represent strains of parasites infecting mothers of congenitally infected children in the U.S. 51 seronegative samples and 13 samples from recently infected persons known to be IgG/IgM positive within the prior 2.7 months also were tested. Interpretation was confirmed by two blinded observers. A comparison of costs for POC vs. commercial laboratory testing methods was performed.We found that this new Toxoplasma ICT IgG-IgM POC test was highly sensitive (100%) and specific (100%) for distinguishing IgG/IgM-positive from negative sera. Use of such reliable POC tests can be cost-saving and benefit patients.Our work demonstrates that the Toxoplasma ICT IgG-IgM test can function reliably as a point-of-care test to diagnose Toxoplasma gondii infection in the U.S. This provides an opportunity to improve maternal-fetal care by using approaches, diagnostic tools, and medicines already available. This infection has serious, lifelong consequences for infected persons and their families. From the present study, it appears a simple, low-cost POC test is now available to help prevent morbidity/disability, decrease cost, and make gestational screening feasible. It also offers new options for improved prenatal care in low- and middle-income countries.

    View details for PubMedID 28650970

  • Do systematic reviews on pediatric topics need special methodological considerations? BMC pediatrics Farid-Kapadia, M., Askie, L., Hartling, L., Contopoulos-Ioannidis, D., Bhutta, Z. A., Soll, R., Moher, D., Offringa, M. 2017; 17 (1): 57-?


    Systematic reviews are key tools to enable decision making by healthcare providers and policymakers. Despite the availability of the evidence based Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA-2009 and PRISMA-P 2015) statements that were developed to improve the transparency and quality of reporting of systematic reviews, uncertainty on how to deal with pediatric-specific methodological challenges of systematic reviews impairs decision-making in child health. In this paper, we identify methodological challenges specific to the design, conduct and reporting of pediatric systematic reviews, and propose a process to address these challenges.One fundamental decision at the outset of a systematic review is whether to focus on a pediatric population only, or to include both adult and pediatric populations. Both from the policy and patient care point of view, the appropriateness of interventions and comparators administered to pre-defined pediatric age subgroup is critical. Decisions need to be based on the biological plausibility of differences in treatment effects across the developmental trajectory in children. Synthesis of evidence from different trials is often impaired by the use of outcomes and measurement instruments that differ between trials and are neither relevant nor validated in the pediatric population. Other issues specific to pediatric systematic reviews include lack of pediatric-sensitive search strategies and inconsistent choices of pediatric age subgroups in meta-analyses. In addition to these methodological issues generic to all pediatric systematic reviews, special considerations are required for reviews of health care interventions' safety and efficacy in neonatology, global health, comparative effectiveness interventions and individual participant data meta-analyses. To date, there is no standard approach available to overcome this problem. We propose to develop a consensus-based checklist of essential items which researchers should consider when they are planning (PRISMA-PC-Protocol for Children) or reporting (PRISMA-C-reporting for Children) a pediatric systematic review. Available guidelines including PRISMA do not cover the complexity associated with the conduct and reporting of systematic reviews in the pediatric population; they require additional and modified standards for reporting items. Such guidance will facilitate the translation of knowledge from the literature to bedside care and policy, thereby enhancing delivery of care and improving child health outcomes.

    View details for DOI 10.1186/s12887-017-0812-1

    View details for PubMedID 28260530

    View details for PubMedCentralID PMC5338083

  • Congenital Toxoplasmosis in France and the United States: One Parasite, Two Diverging Approaches. PLoS neglected tropical diseases Peyron, F., Mc Leod, R., Ajzenberg, D., Contopoulos-Ioannidis, D., Kieffer, F., Mandelbrot, L., Sibley, L. D., Pelloux, H., Villena, I., Wallon, M., Montoya, J. G. 2017; 11 (2)

    View details for DOI 10.1371/journal.pntd.0005222

    View details for PubMedID 28207736

  • Impact of vaccine herd-protection effects in cost-effectiveness analyses of childhood vaccinations. A quantitative comparative analysis. PloS one Holubar, M., Stavroulakis, M. C., Maldonado, Y., Ioannidis, J. P., Contopoulos-Ioannidis, D. 2017; 12 (3)


    Inclusion of vaccine herd-protection effects in cost-effectiveness analyses (CEAs) can impact the CEAs-conclusions. However, empirical epidemiologic data on the size of herd-protection effects from original studies are limited.We performed a quantitative comparative analysis of the impact of herd-protection effects in CEAs for four childhood vaccinations (pneumococcal, meningococcal, rotavirus and influenza). We considered CEAs reporting incremental-cost-effectiveness-ratios (ICERs) (per quality-adjusted-life-years [QALY] gained; per life-years [LY] gained or per disability-adjusted-life-years [DALY] avoided), both with and without herd protection, while keeping all other model parameters stable. We calculated the size of the ICER-differences without vs with-herd-protection and estimated how often inclusion of herd-protection led to crossing of the cost-effectiveness threshold (of an assumed societal-willingness-to-pay) of $50,000 for more-developed countries or X3GDP/capita (WHO-threshold) for less-developed countries.We identified 35 CEA studies (20 pneumococcal, 4 meningococcal, 8 rotavirus and 3 influenza vaccines) with 99 ICER-analyses (55 per-QALY, 27 per-LY and 17 per-DALY). The median ICER-absolute differences per QALY, LY and DALY (without minus with herd-protection) were $15,620 (IQR: $877 to $48,376); $54,871 (IQR: $787 to $115,026) and $49 (IQR: $15 to $1,636) respectively. When the target-vaccination strategy was not cost-saving without herd-protection, inclusion of herd-protection always resulted in more favorable results. In CEAs that had ICERs above the cost-effectiveness threshold without herd-protection, inclusion of herd-protection led to crossing of that threshold in 45% of the cases. This impacted only CEAs for more developed countries, as all but one CEAs for less developed countries had ICERs below the WHO-cost-effectiveness threshold even without herd-protection. In several analyses, recommendation for the adoption of the target vaccination strategy depended on the inclusion of the herd protection effect.Inclusion of herd-protection effects in CEAs had a substantial impact in the estimated ICERs and made target-vaccination strategies more attractive options in almost half of the cases where ICERs were above the societal-willingness to pay threshold without herd-protection. More empirical epidemiologic data are needed to determine the size of herd-protection effects across diverse settings and also the size of negative vaccine effects, e.g. from serotype substitution.

    View details for DOI 10.1371/journal.pone.0172414

    View details for PubMedID 28249046

  • Routinely collected data may usefully supplement randomised controlled data on treatment effects for mortality Reply BMJ-BRITISH MEDICAL JOURNAL Hemkens, L. G., Contopoulos-Ioannidis, D. G., Ioannidis, J. A. 2016; 355: i6747

    View details for PubMedID 27986652

  • Comparative rates of harms in randomized trials from more developed versus less developed countries may be different JOURNAL OF CLINICAL EPIDEMIOLOGY Contopoulos-Ioannidis, D., Tseretopoulou, X., Ancker, M., Walterspiel, J. N., Panagiotou, O. A., Maldonado, Y., Ioannidis, J. P. 2016; 78: 10-21


    We set up to evaluate the relative risk of harms in trials performed in less developed vs. more developed countries.Meta-epidemiologic evaluation using the Cochrane Database of Systematic Reviews. We considered meta-analyses with at least one randomized clinical trial (RCT) in a less developed country and one RCT in a more developed country. We targeted severe adverse events (AEs), discontinuations due to AEs, any AE, organ system-specific AEs, individual AEs, and all discontinuations due to any reason. We estimated the relative odds ratio (ROR) of harms between more and less developed countries for each topic and the summary ROR (sROR) across topics under each category of harms.We identified 42 systematic reviews (128 meta-analyses, 521 independent RCTs). Summary sRORs did not differ significantly from 1.00 for any harm category. Nominally significant RORs were found in only 6/128 meta-analyses. However, in 27% (35/128) of meta-analyses the ROR point estimates indicated relative differences between country settings >2-fold. Considering also ROR 95% confidence intervals, in 92% (118/128) of meta-analyses one could not exclude a 2-fold difference in both directions.We identified limited comparative evidence on harms in trials from these two country settings. Substantial differences in the risk point estimates were common; the potential for modest differences could rarely be excluded with confidence.

    View details for DOI 10.1016/j.jclinepi.2016.02.032

    View details for PubMedID 27063207

  • Routinely collected data and comparative effectiveness evidence: promises and limitations CANADIAN MEDICAL ASSOCIATION JOURNAL Hemkens, L. G., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2016; 188 (8): E158-E164

    View details for DOI 10.1503/cmaj.150653

    View details for PubMedID 26883316

  • Effect of long-term antibiotic use on weight in adolescents with acne. journal of antimicrobial chemotherapy Contopoulos-Ioannidis, D. G., Ley, C., Wang, W., Ma, T., Olson, C., Shi, X., Luft, H. S., Hastie, T., Parsonnet, J. 2016; 71 (4): 1098-1105


    Antibiotics increase weight in farm animals and may cause weight gain in humans. We used electronic health records from a large primary care organization to determine the effect of antibiotics on weight and BMI in healthy adolescents with acne.We performed a retrospective cohort study of adolescents with acne prescribed ≥4 weeks of oral antibiotics with weight measurements within 18 months pre-antibiotics and 12 months post-antibiotics. We compared within-individual changes in weight-for-age Z-scores (WAZs) and BMI-for-age Z-scores (BMIZs). We used: (i) paired t-tests to analyse changes between the last pre-antibiotics versus the first post-antibiotic measurements; (ii) piecewise-constant-mixed models to capture changes between mean measurements pre- versus post-antibiotics; (iii) piecewise-linear-mixed models to capture changes in trajectory slopes pre- versus post-antibiotics; and (iv) χ(2) tests to compare proportions of adolescents with ≥0.2 Z-scores WAZ or BMIZ increase or decrease.Our cohort included 1012 adolescents with WAZs; 542 also had BMIZs. WAZs decreased post-antibiotics in all analyses [change between last WAZ pre-antibiotics versus first WAZ post-antibiotics = -0.041 Z-scores (P < 0.001); change between mean WAZ pre- versus post-antibiotics = -0.050 Z-scores (P < 0.001); change in WAZ trajectory slopes pre- versus post-antibiotics = -0.025 Z-scores/6 months (P = 0.002)]. More adolescents had a WAZ decrease post-antibiotics ≥0.2 Z-scores than an increase (26% versus 18%; P < 0.001). Trends were similar, though not statistically significant, for BMIZ changes.Contrary to original expectations, long-term antibiotic use in healthy adolescents with acne was not associated with weight gain. This finding, which was consistent across all analyses, does not support a weight-promoting effect of antibiotics in adolescents.

    View details for DOI 10.1093/jac/dkv455

    View details for PubMedID 26782773

    View details for PubMedCentralID PMC4790625

  • Current use of routinely collected health data to complement randomized controlled trials: a meta-epidemiological survey. CMAJ open Hemkens, L. G., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2016; 4 (2): E132-40


    Studies that use routinely collected health data (RCD studies) are advocated to complement evidence from randomized controlled trials (RCTs) for comparative effectiveness research and to inform health care decisions when RCTs would be unfeasible. We aimed to evaluate the current use of routinely collected health data to complement RCT evidence.We searched PubMed for RCD studies published to 2010 that evaluated the comparative effectiveness of medical treatments on mortality using propensity scores. We identified RCTs of the same treatment comparisons and evaluated how frequently the RCD studies analyzed treatments that had not been compared previously in randomized trials. When RCTs did exist, we noted the claimed motivations for each RCD study. We also analyzed the citation impact of the RCD studies.Of 337 eligible RCD studies identified, 231 (68.5%) analyzed treatments that had already been compared in RCTs. The study investigators rarely claimed that it would be unethical (6/337) or difficult (18/337) to perform RCTs on the same question. Evidence from RCTs was mentioned or cited by authors of 213 RCD studies. The most common motivations for conducting the RCD studies were alleged limited generalizability of trial results to the "real world" (37.6%), evaluation of specific outcomes (31.9%) or specific populations (23.5%), and inconclusive or inconsistent evidence from randomized trials (25.8%). Studies evaluating "real world" effects had the lowest citation impact.Most of the RCD studies we identified explored comparative treatment effects that had already been investigated in RCTs. The objective of such studies needs to shift more toward answering pivotal questions that are not supported by trial evidence or for which RCTs would be unfeasible.

    View details for DOI 10.9778/cmajo.20150036

    View details for PubMedID 27398355

  • Agreement of treatment effects for mortality from routinely collected data and subsequent randomized trials: meta-epidemiological survey BMJ-BRITISH MEDICAL JOURNAL Hemkens, L. G., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2016; 352


     To assess differences in estimated treatment effects for mortality between observational studies with routinely collected health data (RCD; that are published before trials are available) and subsequent evidence from randomized controlled trials on the same clinical question. Meta-epidemiological survey. PubMed searched up to November 2014. Eligible RCD studies were published up to 2010 that used propensity scores to address confounding bias and reported comparative effects of interventions for mortality. The analysis included only RCD studies conducted before any trial was published on the same topic. The direction of treatment effects, confidence intervals, and effect sizes (odds ratios) were compared between RCD studies and randomized controlled trials. The relative odds ratio (that is, the summary odds ratio of trial(s) divided by the RCD study estimate) and the summary relative odds ratio were calculated across all pairs of RCD studies and trials. A summary relative odds ratio greater than one indicates that RCD studies gave more favorable mortality results. The evaluation included 16 eligible RCD studies, and 36 subsequent published randomized controlled trials investigating the same clinical questions (with 17 275 patients and 835 deaths). Trials were published a median of three years after the corresponding RCD study. For five (31%) of the 16 clinical questions, the direction of treatment effects differed between RCD studies and trials. Confidence intervals in nine (56%) RCD studies did not include the RCT effect estimate. Overall, RCD studies showed significantly more favorable mortality estimates by 31% than subsequent trials (summary relative odds ratio 1.31 (95% confidence interval 1.03 to 1.65; I(2)=0%)). Studies of routinely collected health data could give different answers from subsequent randomized controlled trials on the same clinical questions, and may substantially overestimate treatment effects. Caution is needed to prevent misguided clinical decision making.

    View details for DOI 10.1136/bmj.i493

    View details for PubMedID 26858277

  • Reply to letter by Ferrante di Ruffano et al.: Patient outcomes in randomized comparisons of diagnostic tests are still the ultimate judge JOURNAL OF CLINICAL EPIDEMIOLOGY Siontis, K. C., Siontis, G. C., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2016; 69: 267-268

    View details for DOI 10.1016/j.jclinepi.2015.06.012

    View details for PubMedID 26130596

  • PRISMA-Children (C) and PRISMA-Protocol for Children (P-C) Extensions: a study protocol for the development of guidelines for the conduct and reporting of systematic reviews and meta-analyses of newborn and child health research BMJ OPEN Kapadia, M. Z., Askie, L., Hartling, L., Contopoulos-Ioannidis, D., Bhutta, Z. A., Soll, R., Moher, D., Offringa, M. 2016; 6 (4)


    Paediatric systematic reviews differ from adult systematic reviews in several key aspects such as considerations of child tailored interventions, justifiable comparators, valid outcomes and child sensitive search strategies. Available guidelines, including PRISMA-P (2015) and PRISMA (2009), do not cover all the complexities associated with reporting systematic reviews in the paediatric population. Using a collaborative, multidisciplinary structure, we aim to develop evidence-based and consensus-based PRISMA-P-C (Protocol for Children) and PRISMA-C (Children) Extensions to guide paediatric systematic review protocol and completed review reporting.This project's methodology follows published recommendations for developing reporting guidelines and involves the following six phases; (1) establishment of a steering committee representing key stakeholder groups; (2) a scoping review to identify potential Extension items; (3) three types of consensus activities including meetings of the steering committee to achieve high-level decisions on the content and methodology of the Extensions, a survey of key stakeholders to generate a list of possible items to include in the Extensions and a formal consensus meeting to select the reporting items to add to, or modify for, the Extension; (4) the preliminary checklist items generated in phase III will be evaluated against the existing evidence and reporting practices in paediatric systematic reviews; (5) extension statements and explanation and elaboration documents will provide detailed advice for each item and examples of good reporting; (6) development and implementation of effective knowledge translation of the extension checklist, and an evaluation of the Extensions by key stakeholders.This protocol was considered a quality improvement project by the Hospital for Sick Children's Ethics Committee and did not require ethical review. The resultant checklists, jointly developed with all relevant stakeholders, will be disseminated through peer-reviewed journals as well as national and international conference presentations. Endorsement of the checklist will be sought simultaneously in multiple journals.

    View details for DOI 10.1136/bmjopen-2015-010270

    View details for Web of Science ID 000376391400053

    View details for PubMedID 27091820

    View details for PubMedCentralID PMC4838710

  • Clustering of Toxoplasma gondii Infections Within Families of Congenitally Infected Infants. Clinical infectious diseases Contopoulos-Ioannidis, D., Wheeler, K. M., Ramirez, R., Press, C., Mui, E., Zhou, Y., Van Tubbergen, C., Prasad, S., Maldonado, Y., Withers, S., Boyer, K. M., Noble, A. G., Rabiah, P., Swisher, C. N., Heydemann, P., Wroblewski, K., Karrison, T., Grigg, M. E., Montoya, J. G., McLeod, R. 2015; 61 (12): 1815-1824


    Family clusters and epidemics of toxoplasmosis in North, Central, and South America led us to determine whether fathers of congenitally infected infants in the National Collaborative Chicago-Based Congenital Toxoplasmosis Study (NCCCTS) have a high incidence of Toxoplasma gondii infection.We analyzed serum samples collected from NCCCTS families between 1981 and 2013. Paternal serum samples were tested for T. gondii antibodies with immunoglobulin (Ig) G dye test and IgM enzyme-linked immunosorbent assay. Additional testing of paternal serum samples was performed with differential-agglutination and IgG avidity tests when T. gondii IgG and IgM results were positive and serum samples were collected by the 1-year visit of the congenitally infected child. Prevalence of paternal seropositivity and incidence of recent infection were calculated. We analyzed whether certain demographics, maternal parasite serotype, risk factors, or maternal/infant clinical manifestations were associated with paternal T. gondii infection status.Serologic testing revealed a high prevalence (29 of 81; 36%) of T. gondii infection in fathers, relative to the average seropositivity rate of 9.8% for boys and men aged 12-49 years in the United States between 1994 and 2004 (P < .001). Moreover, there was a higher-than-expected incidence of recent infections among fathers with serum samples collected by the 1-year visit of their child (6 of 45; 13%; P < .001). No demographic patterns or clinical manifestations in mothers or infants were associated with paternal infections, except for sandbox exposure.The high prevalence of chronic and incidence of recent T. gondii infections in fathers of congenitally infected children indicates that T. gondii infections cluster within families in North America. When a recently infected person is identified, family clustering and community risk factors should be investigated for appropriate clinical management.

    View details for DOI 10.1093/cid/civ721

    View details for PubMedID 26405150

  • Trends in Hospitalizations for Intussusception in California in Relationship to the Introduction of New Rotavirus Vaccines, 1985-2010. Pediatric infectious disease journal Contopoulos-Ioannidis, D. G., Halpern, M. S., Maldonado, Y. 2015; 34 (7): 712-717


    The new rotavirus vaccines RV5 and RV1 have been associated with small increase in intussusception risk in active vaccine surveillance studies. It is unclear what the impact might be on the overall trends of intussusception hospitalizations at a large population basis.We conducted an ecological study of hospital discharges of infants with intussusception discharge diagnosis using the California Office of Statewide Health Planning and Development database (1985-2010). We measured incidence rates (IR) of intussusception hospitalizations per 100,000 births within 3 periods (1985-1997; 2000-2005; 2006-2010) related to past, pre-introduction and post-introduction of the new rotavirus vaccines. We estimated slopes of yearly IRs within each period, changes in slopes between periods and IR ratios (IRR) of the mean IRs between periods. We did subgroup analyses for 5 age-subgroups. We also analyzed intussusception hospitalizations of infants who also had a surgical repair and/or radiologic reduction procedure code (restricted cohort).We identified 6241 intussusception hospitalizations; 4696 also had pertinent procedure codes. There was an upward trend in yearly IRs during 2006-2010 (+2 excess cases per 100,000 births per year; P = 0.023); the change in slopes between 2006-2010 and 2000-2005 was +3.2 excess cases per 100,000 births per year (P = 0.052), and the IR in 2006-2010 was 10% higher than in 2000-2005 (IRR: 1.10; 95% confidence intervals: 1.01-1.19). The IRR in 2006-2010 versus 2000-2005 for the 6-14 weeks age-subgroup was 1.90 (95% confidence intervals: 1.33-2.74). In the restricted cohort, trends were similar, though not nominally significant.We documented at a population-level a small increased risk in intussusception hospitalizations post-introduction of the new rotavirus vaccines.

    View details for DOI 10.1097/INF.0000000000000653

    View details for PubMedID 26069946

  • Seasonal variation of acute toxoplasmic lymphadenopathy in the United States EPIDEMIOLOGY AND INFECTION Contopoulos-Ioannidis, D., Talucod, J., Maldonado, Y., Montoya, J. G. 2015; 143 (9): 1893-1897


    SUMMARY We describe the seasonal variation of acute toxoplasmosis in the United States. Acute toxoplasmic lymphadenopathy (ATL) can be a surrogate of acute toxoplasmosis in patients in whom the date of onset of lymphadenopathy matches the window of acute infection predicted by serological tests performed at a reference laboratory. We used the electronic database of the Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) (1997-2011) to identify cases of ATL. We tested the uniformity of distribution of ATL cases per month, across the 12 calendar months, using circular statistics uniformity tests. We identified 112 consecutive cases of ATL. The distribution of cases was not uniform across the 12 calendar months. We observed the highest peak of cases in December and a second highest peak in September. Similar months were identified in patients with acute toxoplasmosis in rural areas in France. The results were similar when we performed weighted analyses, weighting for the total number of Toxoplasma gondii IgG tests performed per month in the PAMF-TSL laboratory. This is the largest study to date of the seasonal variation of ATL in the United States. Physicians should advise high-risk individuals to avoid risk factors associated with T. gondii infections especially around those months.

    View details for DOI 10.1017/S0950268814002945

    View details for PubMedID 25410401

  • Diagnostic tests often fail to lead to changes in patient outcomes. Journal of clinical epidemiology Siontis, K. C., Siontis, G. C., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2014; 67 (6): 612-621


    To evaluate the effects of diagnostic testing on patient outcomes in a large sample of diagnostic randomized controlled trials (D-RCTs) and to examine whether the effects for patient outcomes correlate with the effects on management and with diagnostic accuracy.We considered D-RCTs that evaluated diagnostic interventions for any condition and reported effectiveness data on one or more patient outcomes. We calculated odds ratios for patient outcomes and outcomes pertaining to the use of further diagnostic and therapeutic interventions and the diagnostic odds ratio (DOR) for the accuracy of experimental tests.One hundred forty trials (153 comparisons) were eligible. Patient outcomes were significantly improved in 28 comparisons (18%). There was no concordance in significance and direction of effects between the patient outcome and outcomes for use of further diagnostic or therapeutic interventions (weighted κ 0.02 and 0.09, respectively). The effect size for the patient outcome did not correlate with the effect sizes for use of further diagnostic (r = 0.05; P = 0.78) or therapeutic interventions (r = 0.18; P = 0.08) or the experimental intervention DOR in the same trial (r = -0.24; P = 0.51).Few tests have well-documented benefits on patient outcomes. Diagnostic performance or the effects on management decisions are not necessarily indicative of patient benefits.

    View details for DOI 10.1016/j.jclinepi.2013.12.008

    View details for PubMedID 24679598

  • Diagnostic tests often fail to lead to changes in patient outcomes JOURNAL OF CLINICAL EPIDEMIOLOGY Siontis, K. C., Siontis, G. C., Contopoutos-Ioannidis, D. G., Ioannidis, J. P. 2014; 67 (6): 612-621


    To evaluate the effects of diagnostic testing on patient outcomes in a large sample of diagnostic randomized controlled trials (D-RCTs) and to examine whether the effects for patient outcomes correlate with the effects on management and with diagnostic accuracy.We considered D-RCTs that evaluated diagnostic interventions for any condition and reported effectiveness data on one or more patient outcomes. We calculated odds ratios for patient outcomes and outcomes pertaining to the use of further diagnostic and therapeutic interventions and the diagnostic odds ratio (DOR) for the accuracy of experimental tests.One hundred forty trials (153 comparisons) were eligible. Patient outcomes were significantly improved in 28 comparisons (18%). There was no concordance in significance and direction of effects between the patient outcome and outcomes for use of further diagnostic or therapeutic interventions (weighted κ 0.02 and 0.09, respectively). The effect size for the patient outcome did not correlate with the effect sizes for use of further diagnostic (r = 0.05; P = 0.78) or therapeutic interventions (r = 0.18; P = 0.08) or the experimental intervention DOR in the same trial (r = -0.24; P = 0.51).Few tests have well-documented benefits on patient outcomes. Diagnostic performance or the effects on management decisions are not necessarily indicative of patient benefits.

    View details for DOI 10.1016/j.jclinepi.2013.12.008

    View details for Web of Science ID 000335610000003

  • Safety of medical interventions in children versus adults. Pediatrics Lathyris, D., Panagiotou, O. A., Baltogianni, M., Ioannidis, J. P., Contopoulos-Ioannidis, D. G. 2014; 133 (3): e666-73


    Compare the risk of harm from pharmacologic interventions in pediatric versus adult randomized controlled trials (RCTs).We used systematic reviews from the Cochrane Database of Systematic Reviews. We considered separately 7 categories of harms/harm-related end points: severe harms, withdrawals due to harms, any harm, organ system-level harms, specific harms, withdrawals for any reason, and mortality. Systematic reviews with quantitative synthesis from at least 1 adult and 1 pediatric RCT for any of those end points were eligible. We calculated the summary odds ratio (experimental versus control intervention) in adult and pediatric trials/meta-analysis; the relative odds ratio (ROR) in adults versus children per meta-analysis; and the summary ROR (sROR) across all meta-analyses for each end point. ROR <1 means that the experimental intervention fared worse in children than adults.We identified 176 meta-analyses for 52 types of harms/harm-related end points with 669 adult and 184 pediatric RCTs. Of those, 165 had sufficient data for ROR estimation. sRORs showed statistically significant discrepancy between adults and children only for headache (sROR 0.82; 95% confidence interval 0.70-0.96). Nominally significant discrepancies for specific harms were identified in 12 of 165 meta-analyses (RORs <1 in 7, ROR >1 in 5). In 36% of meta-analyses, the ROR estimates suggested twofold or greater differences between children and adults, and the 95% confidence intervals could exclude twofold differences only in 18% of meta-analyses.Available evidence on harms/harm-related end points from pharmacologic interventions has large uncertainty. Extrapolation of evidence from adults to children may be tenuous. Some clinically important discrepancies were identified.

    View details for DOI 10.1542/peds.2013-3128

    View details for PubMedID 24567023

  • Acute Toxoplasma gondii Infection among Family Members in the United States EMERGING INFECTIOUS DISEASES Contopoulos-Ioannidis, D. G., Maldonado, Y., Montoya, J. G. 2013; 19 (12): 1981-1984


    We investigated 32 families of persons with acute toxoplasmosis in which > or = 1 other family member was tested for Toxoplasma gondii infection; 18 (56%) families had > or = 1 additional family member with acute infection. Family members of persons with acute toxoplasmosis should be screened for infection, especially pregnant women and immunocompromised persons.

    View details for DOI 10.3201/eid1912.121892

    View details for Web of Science ID 000327826600012

    View details for PubMedID 24274896

    View details for PubMedCentralID PMC3840881

  • Most meta-analyses of drug interventions have narrow scopes and many focus on specific agents JOURNAL OF CLINICAL EPIDEMIOLOGY Haidich, A., Pilalas, D., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2013; 66 (4): 371-378


    To assess the extent to which meta-analysis publications of drugs and biologics focus on specific named agents or even only a single agent, and identify characteristics associated with such focus.We evaluated 499 articles with meta-analyses published in 2010 and estimated how many did not cover all the available comparisons of tested interventions for a given condition (not all-inclusive); focused on specific named agent(s), or focused strictly on comparisons of only one specific active agent vs. placebo/no treatment or different doses/schedules.Of 499 eligible articles, 403 (80.8%) were not all-inclusive, 214 (42.9%) covered only specific named agent(s), and 74 (14.8%) examined only comparisons with one active agent vs. placebo/no treatment or different doses/schedules. Only 39 articles (7.8%) covered all possible indications for the examined agent(s). After adjusting for type of treatment/field, focus on specific named agent(s) was associated with publication in journal venues (odds ratio [OR]: 1.95; 95% confidence interval [CI]: 1.17-3.26) vs. Cochrane, industry sponsoring (OR: 3.94; 95% CI: 1.66-10.66), and individual patient data analyses (OR: 6.59; 95% CI: 2.24-19.39). Individual patient data analyses primarily (29/34) focused on specific named agent(s).The scope of meta-analysis publications frequently is narrow and shaped to serve particular agents.

    View details for DOI 10.1016/j.jclinepi.2012.10.014

    View details for Web of Science ID 000315935100006

    View details for PubMedID 23384590

  • Patient Safety Strategies Targeted at Diagnostic Errors A Systematic Review ANNALS OF INTERNAL MEDICINE McDonald, K. M., Matesic, B., Contopoulos-Ioannidis, D. G., Lonhart, J., Schmidt, E., Pineda, N., Ioannidis, J. P. 2013; 158 (5): 381-?


    Missed, delayed, or incorrect diagnosis can lead to inappropriate patient care, poor patient outcomes, and increased cost. This systematic review analyzed evaluations of interventions to prevent diagnostic errors. Searches used MEDLINE (1966 to October 2012), the Agency for Healthcare Research and Quality's Patient Safety Network, bibliographies, and prior systematic reviews. Studies that evaluated any intervention to decrease diagnostic errors in any clinical setting and with any study design were eligible, provided that they addressed a patient-related outcome. Two independent reviewers extracted study data and rated study quality. There were 109 studies that addressed 1 or more intervention categories: personnel changes (n = 6), educational interventions (n = 11), technique (n = 23), structured process changes (n = 27), technology-based systems interventions (n = 32), and review methods (n = 38). Of 14 randomized trials, which were rated as having mostly low to moderate risk of bias, 11 reported interventions that reduced diagnostic errors. Evidence seemed strongest for technology-based systems (for example, text message alerting) and specific techniques (for example, testing equipment adaptations). Studies provided no information on harms, cost, or contextual application of interventions. Overall, the review showed a growing field of diagnostic error research and categorized and identified promising interventions that warrant evaluation in large studies across diverse settings.

    View details for Web of Science ID 000316058600004

    View details for PubMedID 23460094

  • Comparative effect sizes in randomised trials from less developed and more developed countries: meta-epidemiological assessment BRITISH MEDICAL JOURNAL Panagiotou, O. A., Contopoulos-Ioannidis, D. G., Ioannidis, J. P., Rehnborg, C. F. 2013; 346


    To compare treatment effects from randomised trials conducted in more developed versus less developed countries.Meta-epidemiological study.Cochrane Database of Systematic Reviews (August 2012).Meta-analyses with mortality outcomes including data from at least one randomised trial conducted in a less developed country and one in a more developed country. Relative risk estimates of more versus less developed countries were compared by calculating the relative relative risks for each topic and the summary relative relative risks across all topics. Similar analyses were performed for the primary binary outcome of each topic.139 meta-analyses with mortality outcomes were eligible. No nominally significant differences between more developed and less developed countries were found for 128 (92%) meta-analyses. However, differences were beyond chance in 11 (8%) cases, always showing more favourable treatment effects in trials from less developed countries. The summary relative relative risk was 1.12 (95% confidence interval 1.06 to 1.18; P<0.001; I(2)=0%), suggesting significantly more favourable mortality effects in trials from less developed countries. Results were similar for meta-analyses with nominally significant treatment effects for mortality (1.15), meta-analyses with recent trials (1.14), and when excluding trials from less developed countries that subsequently became more developed (1.12). For the primary binary outcomes (127 meta-analyses), 20 topics had differences in treatment effects beyond chance (more favourable in less developed countries in 15/20 cases).Trials from less developed countries in a few cases show significantly more favourable treatment effects than trials in more developed countries and, on average, treatment effects are more favourable in less developed countries. These discrepancies may reflect biases in reporting or study design as well as genuine differences in baseline risk or treatment implementation and should be considers when generalising evidence across different settings.

    View details for DOI 10.1136/bmj.f707

    View details for Web of Science ID 000315087700003

    View details for PubMedID 23403829

    View details for PubMedCentralID PMC3570069

  • Empirical Evaluation of Age Groups and Age-Subgroup Analyses in Pediatric Randomized Trials and Pediatric Meta-analyses PEDIATRICS Contopoulos-Ioannidis, D. G., Seto, I., Hamm, M. P., Thomson, D., Hartling, L., Ioannidis, J. P., Curtis, S., Constantin, E., Batmanabane, G., Klassen, T., Williams, K. 2012; 129: S161-S184


    An important step toward improvement of the conduct of pediatric clinical research is the standardization of the ages of children to be included in pediatric trials and the optimal age-subgroups to be analyzed.We set out to evaluate empirically the age ranges of children, and age-subgroup analyses thereof, reported in recent pediatric randomized clinical trials (RCTs) and meta-analyses. First, we screened 24 RCTs published in Pediatrics during the first 6 months of 2011; second, we screened 188 pediatric RCTs published in 2007 in the Cochrane Central Register of Controlled Trials; third, we screened 48 pediatric meta-analyses published in the Cochrane Database of Systematic Reviews in 2011. We extracted information on age ranges and age-subgroups considered and age-subgroup differences reported.The age range of children in RCTs published in Pediatrics varied from 0.1 to 17.5 years (median age: 5; interquartile range: 1.8-10.2) and only 25% of those presented age-subgroup analyses. Large variability was also detected for age ranges in 188 RCTs from the Cochrane Central Register of Controlled Trials, and only 28 of those analyzed age-subgroups. Moreover, only 11 of 48 meta-analyses had age-subgroup analyses, and in 6 of those, only different studies were included. Furthermore, most of these observed differences were not beyond chance.We observed large variability in the age ranges and age-subgroups of children included in recent pediatric trials and meta-analyses. Despite the limited available data, some age-subgroup differences were noted. The rationale for the selection of particular age-subgroups deserves further study.

    View details for DOI 10.1542/peds.2012-0055J

    View details for PubMedID 22661763

  • Standard 6: Age Groups for Pediatric Trials PEDIATRICS Williams, K., Thomson, D., Seto, I., Contopoulos-Ioannidis, D. G., Ioannidis, J. P., Curtis, S., Constantin, E., Batmanabane, G., Hartling, L., Klassen, T. 2012; 129: S153-S160

    View details for DOI 10.1542/peds.2012-0055I

    View details for Web of Science ID 000307396800008

    View details for PubMedID 22661762

  • Claims for improved survival from systemic corticosteroids in diverse conditions: an umbrella review EUROPEAN JOURNAL OF CLINICAL INVESTIGATION Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2012; 42 (3): 233-244


    Systemic corticosteroids have been proposed for numerous indications and there are many claims that corticosteroids can reduce mortality in diverse conditions.We performed an umbrella, agenda-wide review of the evidence on systemic corticosteroids and mortality, focusing primarily on large trials (defined as those with > 100 deaths) and meta-analyses. Searches were performed in PubMed and Cochrane Central Register of Controlled Trials (last update February 2011). We also examined whether spurious subset analyses may be responsible for claims of survival benefits in indications where only small trials had been available.Among 257 identified randomized trials with mortality data in their abstract, we found 14 large trials pertaining to 10 different indications. Although 10 of these 14 trials have reported statistically significant survival differences in subset analyses, none shows a nominally statistically significant (P < 0·05) decrease in death risk for any of the tested conditions when all deaths on all randomized patients are analysed. Meta-analyses for these conditions show statistically significant reductions in mortality only with antenatal corticosteroids for preterm labour (relative risk 0·77, 95% CI, 0·67-0·89) and in tuberculous meningitis (relative risk 0·78, 95% CI, 0·67-0·91). For conditions without any large trials, statistically significant reductions in mortality in meta-analyses were noted for Pneumocystis pneumonia (relative risk 0·54, 95% CI, 0·38-0·79) and alcoholic hepatitis (relative risk 0·63, 95% CI, 0·50-0·80). Many small trials that claim significant benefits, even those for classic indications such as typhoid fever and tetanus, have shown these benefits only in subset analyses.Corticosteroids have been documented to decrease mortality in some indications, in particular, antenatal use for preterm labour, tuberculous meningitis, Pneumocystis pneumonia, and alcoholic hepatitis. Many postulated benefits of corticosteroids on mortality may reflect 'vibration of treatment effects' leading to false-positive claims from spurious subset analyses and even for standard indications, such biases may have inflated the treatment effect estimates. More large trials are needed for serious, common conditions where use of corticosteroids is proposed.

    View details for DOI 10.1111/j.1365-2362.2011.02584.x

    View details for PubMedID 21880039

  • Different Black Box Warning Labeling for Same-Class Drugs JOURNAL OF GENERAL INTERNAL MEDICINE Panagiotou, O. A., Contopoulos-Ioannidis, D. G., Papanikolaou, P. N., Ntzani, E. E., Ioannidis, J. P. 2011; 26 (6): 603-610


    Black box warnings (BBWs) are the strongest medication-related safety warnings in a drug's labeling information and highlight major risks. Absence of a BBW or asynchronous addition of a BBW among same-class drugs could have major implications.We identified the 20 top-selling drugs in 2008 (10 with BBWs and 10 without BBWs on their label) that belonged to different drug classes. We collected labeling information on all drugs belonging in these 20 classes, and recorded differences in the presence and timing of acquisition of BBWs for same-class drugs.Across the 20 evaluated drug classes, we identified 176 different agents, of which 7 had been withdrawn for safety reasons. The reasons for the withdrawals became BBWs in other same-class agents only in two of the seven cases. Differences were identified in 9 of the 20 classes corresponding to 15 BBWs that were not present in all drugs of the same class. The information for 10 of the 15 different BBWs were included in the labels of same-class drugs as simple warnings or text, while it was absent entirely in 5 BBWs. The median interval from the time the BBW had appeared in another drug of the same class was 66 months.Differences in BBW labeling in same-class drugs are common and shape impressions about the safety of similar agents. BBW labeling needs to become more systematic.

    View details for DOI 10.1007/s11606-011-1633-9

    View details for Web of Science ID 000290576600010

    View details for PubMedID 21286838

    View details for PubMedCentralID PMC3101972

  • Comparative Effectiveness of Medical Interventions in Adults Versus Children JOURNAL OF PEDIATRICS Contopoulos-Ioannidis, D. G., Baltogianni, M. S., Ioannidis, J. P. 2010; 157 (2): 322-330


    To estimate the comparative effectiveness of medical interventions in adults versus children.We identified from the Cochrane Database of Systematic Reviews (Issue 1, 2007) meta-analyses with data on at least 1 adult and 1 pediatric randomized trial with binary primary efficacy outcome. For each meta-analysis, we calculated the summary odds ratio of the adult trials and the pediatric trials, respectively; the relative odds ratio (ROR) of the adult versus pediatric odds ratios per meta-analysis; and the summary ROR across all meta-analyses. ROR <1 means that the experimental intervention is more unfavorable in children than adults.Across 128 eligible meta-analyses (1051 adult and 343 pediatric trials), the summary ROR did not show a statistically significant difference between adults and children (0.96; 95% confidence intervals, 0.86 to 1.08). However, in all meta-analyses except for 1, the individual ROR's 95% confidence intervals could not exclude a relative difference in efficacy over 20%. In two-thirds, the relative difference in observed point estimates exceeded 50%. Nine statistically significant discrepancies were identified; 4 of them were also clinically important.Treatment effects are on average similar in adults and children, but available evidence leaves large uncertainty about their relative efficacy. Clinically important discrepancies may occur.

    View details for DOI 10.1016/j.jpeds.2010.02.011

    View details for Web of Science ID 000279871700031

    View details for PubMedID 20434730

  • Reporting and interpretation of SF-36 outcomes in randomised trials: systematic review BRITISH MEDICAL JOURNAL Contopoulos-Ioannidis, D. G., Karvouni, A., Kouri, I., Ioannidis, J. P. 2009; 338


    To determine how often health surveys and quality of life evaluations reach different conclusions from those of primary efficacy outcomes and whether discordant results make a difference in the interpretation of trial findings.Systematic review.PubMed, contact with authors for missing information, and author survey for unpublished SF-36 data.Randomised trials with SF-36 outcomes (the most extensively validated and used health survey instrument for appraising quality of life) that were published in 2005 in 22 journals with a high impact factor.Analyses on the two composite and eight subdomain SF-36 scores that corresponded to the time and mode of analysis of the primary efficacy outcome.Of 1057 screened trials, 52 were identified as randomised trials with SF-36 results (66 separate comparisons). Only eight trials reported all 10 SF-36 scores in the published articles. For 21 of the 66 comparisons, SF-36 results were discordant for statistical significance compared with the results for primary efficacy outcomes. Of 17 statistically significant SF-36 scores where primary outcomes were not also statistically significant in the same direction, the magnitude of effect was small in six, moderate in six, large in three, and not reported in two. Authors modified the interpretation of study findings based on SF-36 results in only two of the 21 discordant cases. Among 100 additional randomly selected trials not reporting any SF-36 information, at least five had collected SF-36 data but only one had analysed it.SF-36 measurements sometimes produce different results from those of the primary efficacy outcomes but rarely modify the overall interpretation of randomised trials. Quality of life and health related survey information should be utilised more systematically in randomised trials.

    View details for DOI 10.1136/bmj.a3006

    View details for Web of Science ID 000263192800001

    View details for PubMedID 19139138

  • Recurrent Rhabdomyolysis in a Patient With Oculocutaneous Albinism Type 1 and Platelet Storage-Pool Deficiency AMERICAN JOURNAL OF MEDICAL GENETICS PART A Contopoulos-Ioannidis, D., Evangeliou, A., ter Laak, H., de Vries, B., Pfundt, R., Schewer, H., Smeitink, J., Tzoufi, M., Makis, A., Marinos, E., Hess, R., Adams, D., Huizing, M., Morava, E. 2008; 146A (23): 3100-3103

    View details for DOI 10.1002/ajmg.a.32569

    View details for Web of Science ID 000261636100020

    View details for PubMedID 19006216

  • Medicine - Life cycle of translational research for medical interventions SCIENCE Contopoulos-Ioannidis, D. G., Alexiou, G. A., Gouvias, T. C., Ioannidis, J. P. 2008; 321 (5894): 1298-1299

    View details for DOI 10.1126/science.1160622

    View details for Web of Science ID 000258914300031

    View details for PubMedID 18772421

  • International ranking systems for universities and institutions: a critical appraisal BMC MEDICINE Ioannidis, J. P., Patsopoulos, N. A., Kavvoura, F. K., Tatsioni, A., Evangelou, E., Kouri, I., Contopoulos-Ioannidis, D. G., Liberopoulos, G. 2007; 5


    Ranking of universities and institutions has attracted wide attention recently. Several systems have been proposed that attempt to rank academic institutions worldwide.We review the two most publicly visible ranking systems, the Shanghai Jiao Tong University 'Academic Ranking of World Universities' and the Times Higher Education Supplement 'World University Rankings' and also briefly review other ranking systems that use different criteria. We assess the construct validity for educational and research excellence and the measurement validity of each of the proposed ranking criteria, and try to identify generic challenges in international ranking of universities and institutions.None of the reviewed criteria for international ranking seems to have very good construct validity for both educational and research excellence, and most don't have very good construct validity even for just one of these two aspects of excellence. Measurement error for many items is also considerable or is not possible to determine due to lack of publication of the relevant data and methodology details. The concordance between the 2006 rankings by Shanghai and Times is modest at best, with only 133 universities shared in their top 200 lists. The examination of the existing international ranking systems suggests that generic challenges include adjustment for institutional size, definition of institutions, implications of average measurements of excellence versus measurements of extremes, adjustments for scientific field, time frame of measurement and allocation of credit for excellence.Naïve lists of international institutional rankings that do not address these fundamental challenges with transparent methods are misleading and should be abandoned. We make some suggestions on how focused and standardized evaluations of excellence could be improved and placed in proper context.

    View details for DOI 10.1186/1741-7015-5-30

    View details for Web of Science ID 000252409300001

    View details for PubMedID 17961208

  • Pharmacogenetics of the response to beta 2 agonist drugs: a systematic overview of the field. Pharmacogenomics Contopoulos-Ioannidis, D. G., Kouri, I., Ioannidis, J. P. 2007; 8 (8): 933-958


    The response to beta2-agonist treatment shows large repeatability within individuals and may thus be determined by genetic influences. Here we present a systematic overview of the available genetic association and linkage data for beta2-agonist treatment response. Systematic searches identified 66 eligible articles, as of March 2007, pertaining either to B2AR gene polymorphisms and short-acting or long-acting beta2-agonists or to another 29 different genes. We systematize these study results according to gene, agent and type of outcomes addressed. The systematic review highlights major challenges in the field, including extreme multiplicity of analyses; lack of consensus for main phenotypes of interest; typically small sample sizes; and poor replicability of the proposed genetic variants. Future studies will benefit from standardization of analyses and outcomes, hypothesis-free genome-wide association testing platforms, potentially additional fine mapping around new discovered variants, and large-scale collaborative studies with prospective plans for replication among several teams, with transparent public recording of all data.

    View details for PubMedID 17716228

  • Genetic predisposition to asthma and atopy RESPIRATION Contopoulos-Ioannidis, D. G., Kouri, I. N., Ioannidis, J. P. 2007; 74 (1): 8-12


    A large number of studies have tried to identify heritable components in the susceptibility to asthma and atopy phenotypes. This review examines the evidence of multigenetic inheritance for these conditions. We identified in the literature at least 372 gene-disease association studies for asthma and 124 for atopy published in the last 6 years. Gene-environment analyses were performed in 41 and 14 articles, respectively, in the same time period. Many postulated associations have been probed with limited sample sizes and will require more extensive replication and large-scale evidence. Meta-analyses have been performed for polymorphisms in 5 genes and provide modest evidence for genetic association of asthma with ADAM33 and TNFA gene polymorphisms. Meta-analyses of linkage studies show that it is unlikely to detect strong linkage peaks for asthma susceptibility. However, linkage was claimed between loci on chromosomes 2, 4, 6, 9, 10, 11 and 15 and total serum IgE levels. Careful definitions and standardization of phenotypes across teams of investigators are important to endorse. New large-scale testing platforms may offer new opportunities for discovering susceptibility gene variants, but they need to be coupled with careful study design, international collaboration, and possibly also dissection of gene-environment interactions.

    View details for DOI 10.1159/000096833

    View details for Web of Science ID 000244565400003

    View details for PubMedID 17190999

  • An empirical evaluation of multifarious outcomes in pharmacogenetics: beta-2 adrenoceptor gene polymorphisms in asthma treatment PHARMACOGENETICS AND GENOMICS Contopoulos-Ioannidis, D. G., Alexiou, G. A., Gouvias, T. C., Ioannidis, J. P. 2006; 16 (10): 705-711


    Pharmacogenetics promises to individualize therapeutics. Concerns, however, exist about the lack of replication of discoveries. Selective use of different endpoints, times of assessment, types of interventions and genetic groups across studies may lead to spurious results. Here, we examined the variability of definitions of endpoints and analyses reported across studies addressing the association of the Arg16Gly and/or Gln27Glu polymorphisms of the beta2-adrenergic receptor gene with clinical response to beta2-agonist therapy in asthma.We systematically calculated the number and type of endpoints and analyses reported across studies and recorded the appraisal of their statistical significance.Across 21 studies, the total number of probed and reported associations was 487 when the multiple endpoints and types of comparisons presented by multiple comparisons were considered (337 for Arg16Gly, 98 for Gln27Glu and 52 for their haplotypes): 465 (95%) were probed only once; only six associations were probed twice and two associations were probed five times, for the same endpoint, time of assessment, type of interventions and genetic group. Most studies (17/21) claimed at least one significant association. Overall, however, 243/487 (49.9%) probed and reported associations were not statistically significant, 120 (24.6%) were of unspecified statistical significance, 86 (17.7%) were statistically significant only for specific selected genetic contrasts and only 38 (7.8%) were genuinely statistically significant for the comparison between all available genetic groups.The multifarious outcomes in this literature are inconsistent across studies and susceptible to selective reporting. The lack of standardization hinders the evaluation of replication validity for reported discoveries.

    View details for Web of Science ID 000203009100002

    View details for PubMedID 17001289

  • Hereditary hyperferritinemia cataract syndrome in three unrelated families of western Greek origin caused by the C39 > G mutation of L-ferritin IRE BLOOD CELLS MOLECULES AND DISEASES Papanikolaou, G., Chandrinou, H., Bouzas, E., Contopoulos-Ioannidis, D., Kalotychou, V., Prentzas, K., Lilakos, K., Asproudis, I., Palaiologou, D., Premetis, E., Papassotiriou, I., Sakellaropoulos, N. 2006; 36 (1): 33-40


    Hereditary hyperferritinemia-cataract syndrome (HHCS) is a well-characterized autosomal dominant disease caused by mutations in the iron responsive element (IRE) of ferritin L-chain (FTL) mRNA. Mutations in the IRE result in reduced binding of the trans-acting iron regulatory proteins (IRPs) and hence in upregulation of ferritin L-chain synthesis. The disease is characterized by increased L-ferritin in serum and tissues and early onset of bilateral cataracts. Iron metabolism is normal, and there is no tissue iron overload. At least 25 nucleotide substitutions and deletions in the L-ferritin IRE have been described in families with HHCS, originating from diverse European, Australian and North American populations. We studied the molecular pathogenesis of HHCS in three unrelated kinderships of western Greek origin, with 19 affected members. We identified a relatively rare C39G mutation located in the hexanucleotide loop of L-ferritin IRE. Computational analysis of mRNA folding of mutant FTL IRE predicted that the C39 > G mutation leads to a rearrangement of base pairing in this critical region, which is likely to modify the IRP binding affinity. All subjects with HHCS were heterozygotes for the same C39G mutation. Clinical and laboratory phenotypes were described. Moreover, there was evidence of an association between this FTL IRE stem-loop mutation and very high ferritin levels. Our findings broaden the list of populations where HHCS has been described.

    View details for DOI 10.1016/j.bcmd.2005.10.003

    View details for Web of Science ID 000234880000006

    View details for PubMedID 16406710

  • Meta-analysis of the association of beta 2-adrenergic receptor polymorphisms with asthma phenotypes JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Contopoulos-Ioannidis, D. G., Manoli, E. N., Ioannidis, J. P. 2005; 115 (5): 963-972


    Two common polymorphisms of the beta2-adrenergic receptor gene (Arg16Gly and Gln27Glu ) have been extensively studied for their possible association with asthma-related phenotypes, but the results of individual studies have been inconclusive.We aimed to integrate quantitatively the available evidence on the association of the Arg16Gly and the Gln27Glu polymorphisms with asthma, nocturnal asthma, asthma severity, and bronchial hyperresponsiveness.Meta-analysis of case-control and cohort studies using random effects models.A total of 28 studies were included in the meta-analysis. The summary estimates suggested that neither the Gly16 nor the Glu27 allele contributes to asthma susceptibility overall (odds ratio [OR], 1.01; 95% CI, 0.90-1.13; and OR, 0.95; 95% CI, 0.83-1.09, respectively) or to bronchial hyperresponsiveness (OR, 0.90; 95% CI, 0.77-1.05; and OR, 1.07; 95% CI, 0.94-1.22, respectively). There was a strong association of Gly16 with nocturnal asthma (OR, 2.20; 95% CI, 1.56-3.11) and a less strong association with severe or moderate rather than milder asthma (OR, 1.42; 95% CI, 1.04-1.94). No such effects were seen for the Glu27 allele (OR, 1.02; 95% CI, 0.74-1.40; and OR, 0.82; 95% CI, 0.59-1.14, respectively). Moreover, there was evidence that Gly16 homozygotes had a much higher risk for nocturnal asthma (OR, 5.15; 95% CI, 2.44-10.84) and asthma severity (OR, 2.84; 95% CI, 1.62-4.96) than the Arg16 homozygotes.The Gly16 allele of the beta2-adrenergic receptor gene predisposes to nocturnal asthma, and this may also explain the association with asthma severity. Neither polymorphism modulates the risk for bronchial hyperresponsiveness or mild asthma.

    View details for DOI 10.1016/j.jaci.2004.12.1119

    View details for Web of Science ID 000229055100011

    View details for PubMedID 15867853

  • Comparison of large versus smaller randomized trials for mental health-related interventions AMERICAN JOURNAL OF PSYCHIATRY Contopoulos-Ioannidis, D. G., Gilbody, S. M., Trikalinos, T. A., Churchill, R., Wahlbeck, K., Ioannidis, J. P. 2005; 162 (3): 578-584


    The extent of disagreement between large and smaller randomized, controlled trials on mental health issues is unknown. The authors aimed to compare the results of large versus smaller trials on mental health-related interventions.The authors screened 161 Cochrane and 254 Database of Abstracts of Reviews of Effectiveness systematic reviews on mental health-related interventions. They identified 16 meta-analyses with at least one "large" randomized trial with sample size >800 and at least one "smaller" trial. Effect sizes were calculated separately for large and smaller trials. Heterogeneity was assessed between all studies, within each group (large and smaller studies), and between large and smaller studies.Significant between-study heterogeneity was seen in five meta-analyses. By random-effects calculations, the results of large and smaller trials differed beyond chance in four meta-analyses (25%). In three of these disagreements (effect of day care on IQ, discontinuation of antidepressants, risperidone versus typical antipsychotics for schizophrenia), the smaller trials showed greater effect sizes than the large trials. The inverse was seen in one case (olanzapine versus typical antipsychotics for schizophrenia). With fixed-effects models, disagreements beyond chance occurred in five cases (31%). In four meta-analyses, the effect size differed over twofold between large and smaller trials. Various quality and design parameters were identified as potential explanations for some disagreements.Large trials are uncommon in mental health. Their results are usually comparable with the results of smaller studies, but major disagreements do occur. Both large and smaller trials should be scrutinized as they offer a continuum of randomized evidence.

    View details for Web of Science ID 000227523500022

    View details for PubMedID 15741476

  • Anticonvulsants for alcohol withdrawal COCHRANE DATABASE OF SYSTEMATIC REVIEWS Polycarpou, A., Papanikolau, P., Ioannidis, J. P., Contopoulos-Ioannidis, D. G. 2005


    Alcohol withdrawal syndrome is a cluster of symptoms that occurs in alcohol-dependent people after cessation or reduction in alcohol use. This systematic review focuses on the evidence of anticonvulsants' use in the treatment of alcohol withdrawal symptoms.To evaluate the effectiveness and safety of anticonvulsants in the treatment of alcohol withdrawal.We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004); MEDLINE (1966 to October 2004); EMBASE (1988 to October 2004) and EU-PSI PSI-Tri database with no language and publication restrictions and references of articles.All randomized controlled trials examining the effectiveness, safety and overall risk-benefit of an anticonvulsant in comparison with a placebo or other pharmacological treatment or another anticonvulsant were considered.The authors independently assessed trial quality extracted data.Forty-eight studies, involving 3610 people were included. Despite the considerable number of randomized controlled trials, there was a variety of outcomes and of different rating scales that led to a limited quantitative synthesis of data. For the anticonvulsant versus placebo comparison, therapeutic success tended to be more common among the anticonvulsant-treated patients (relative risk (RR) 1.32; 95% confidence interval (CI) 0.92 to 1.91), and anticonvulsant tended to show a protective benefit against seizures (RR 0.57; 95% CI 0.27 to 1.19), but no effect reached formal statistical significance. For the anticonvulsant versus other drug comparison, CIWA-Ar score showed non-significant differences for the anticonvulsants compared to the other drugs at the end of treatment (weighted mean difference (WMD) -0.73; 95% CI -1.76 to 0.31). For the subgroup analysis of carbamazepine versus benzodiazepine, a statistically significant protective effect was found for the anticonvulsant (WMD -1.04; 95% CI -1.89 to -0.20), p = 0.02), but this was based on only 260 randomized participants. There was a non-significant decreased incidence of seizures (RR 0.50; 95% CI 0.18 to 1.34) favouring the patients that were treated with anticonvulsants than other drugs, and side-effects tended to be less common in the anticonvulsant-group (RR 0.56; 95% CI 0.31 to 1.02).It is not possible to draw definite conclusions about the effectiveness and safety of anticonvulsants in alcohol withdrawal, because of the heterogeneity of the trials both in interventions and the assessment of outcomes. The extremely small mortality rate in all these studies is reassuring, but data on other safety outcomes are sparse and fragmented.

    View details for DOI 10.1002/14651858.CD00564.pub2

    View details for Web of Science ID 000232202500072

    View details for PubMedID 16034965

  • Treatment options for acute sinusitis in children CURRENT ALLERGY AND ASTHMA REPORTS Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2004; 4 (6): 471-477


    Much controversy exists regarding the best diagnostic method for acute sinusitis, the efficacy of antibiotics, the best choice of antibiotics, the most appropriate duration of therapy, and the efficacy of ancillary measures and nasal corticosteroids. The therapeutic goal is to identify those children who are more likely to have bacterial sinusitis and unlikely to resolve spontaneously, who may require treatment with antibiotics. The inaccuracy of clinical signs and symptoms complicates further the management of these children. Acute sinusitis is expected to resolve spontaneously in most cases, including many cases of bacterial sinusitis. Antibiotics are needed only for a minority of non-self-resolving infections. Based on current resistance considerations, approximately 80% of bacterial infections are expected to respond to standard doses of amoxicillin. High-dose amoxicillin, amoxicillin/clavulanate, or other b-lactam antibiotics should be considered for children at high risk for carrying resistant organisms. Evidence for the effectiveness of ancillary measures is limited.

    View details for Web of Science ID 000230808900008

    View details for PubMedID 15462714

  • Establishment of genetic associations for complex diseases is independent of early study findings EUROPEAN JOURNAL OF HUMAN GENETICS Trikalinos, T. A., Ntzani, E. E., Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 2004; 12 (9): 762-769


    Numerous genetic association studies for complex diseases are performed. Investigators place emphasis on formal statistical significance (P-values < 0.05), but the predictive ability of early statistically significant ('positive') findings is unclear. We scrutinized 55 cumulative meta-analyses of genetic associations (579 studies), in order to assess whether having statistical significance in the earliest (first) published study or in at least half among several (> or =3) early-published studies, or high statistical significance in early studies had any predictive ability for establishing or refuting the presence of the genetic association in subsequent research. In 35 associations, a first study was 'positive' and in 15 associations more than half of the early-published reports were 'positive'. The average publication rate of subsequent studies increased 1.71-fold with a 'positive' first report. When compared against the summary results of subsequent research, sensitivity and specificity were 0.65 and 0.38 for the first reports, and 0.40 and 0.73, respectively, when at least three early studies were considered. First studies also had poor predictive ability, when we considered the estimated attributable fraction and coverage of the 95% confidence interval thereof or higher levels of statistical significance. We conclude that although 'positive' findings in the very first reports provide strong incentive for conducting more studies on a putative genetic epidemiological association, the statistical significance or even the magnitude of the effect of early studies cannot adequately predict eventual establishment of an association. Conversely, many genuine epidemiological associations would be missed, if research were abandoned after early underpowered 'negative' studies.

    View details for DOI 10.1038/sj.ejhg.5201227

    View details for Web of Science ID 000223403900011

    View details for PubMedID 15213707

  • Extended-interval aminoglycoside administration for children: A meta-analysis PEDIATRICS Contopoulos-Ioannidis, D. G., Giotis, N. D., Baliatsa, D. V., Ioannidis, J. P. 2004; 114 (1): E111-E118


    There has been a long-standing debate regarding whether aminoglycosides should be administered on a multiple daily dosing (MDD) or once-daily dosing (ODD) schedule. Several unique characteristics of the aminoglycosides make ODD an attractive and possibly superior alternative to MDD. These include concentration-dependent bactericidal activity; postantibiotic effect, which allows continued efficacy even when serum concentrations fall below expected minimum inhibitory concentrations; decreased risk of adaptive resistance; and diminished accumulation in renal tubules and inner ear.To assess the relative efficacy and toxicity of ODD, compared with MDD, of aminoglycosides among pediatric patients.Randomized, controlled trials among children, evaluating the relative efficacy and toxicity of ODD versus MDD of aminoglycosides, with similar total daily doses in the compared arms, were selected.PubMed (1966-2003) and Embase (1982-2003) databases, the Cochrane Controlled Trials Registry (2003), and references of eligible studies and pediatric review articles were searched.Study population characteristics and outcome data were extracted independently in duplicate, and consensus was reached on all items. The following outcome data were considered: (1) clinical or microbiologic failure, as defined in each study; (2) clinical failure; (3) microbiologic failure; (4) primary nephrotoxicity, ie, any rise in serum creatinine or decrease in creatinine clearance with thresholds as defined in each study; (5) secondary nephrotoxicity, ie, urinary excretion of proteins or phospholipids; and (6) ototoxicity based on pure tone audiometry, brainstem auditory evoked responses, or otoacoustic emissions for neonates and infants, vestibular testing, clinical impression, or any other method. All of the efficacy and toxicity outcomes were evaluated at the end of therapy.Identification of eligible studies and study characteristics: 24 eligible studies published between 1991 and 2003 were identified. Aminoglycosides were used in different clinical settings (neonatal intensive care unit: 6 studies; cystic fibrosis: 3 studies; cancer: 5 studies; urinary tract infections: 4 studies; diverse infectious indications: 5 studies; pediatric intensive care unit: 1 study). Aminoglycosides used included amikacin (9 studies), gentamicin (11 studies), tobramycin (2 studies), netilmicin (2 studies), and tobramycin or netilmicin (1 study).There was no significant difference between ODD and MDD in the clinical failure rate, microbiologic failure rate, and combined clinical or microbiologic failure rates, but trends favored ODD consistently. There was no between-study heterogeneity for any outcome. Efficacy analysis of all trials indicating either clinical or microbiologic failures demonstrated pooled failure rates of 4.6% (23 of 501 cases) in the ODD arms and 6.9% (34 of 494 cases) in the MDD arms. The fixed-effects risk ratio was 0.71 (95% confidence interval [CI]: 0.45-1.11). A statistically significant benefit was seen with ODD over MDD in trials using amikacin, whereas no statistical significance was seen in trials using other antibiotics. The pooled clinical failure rates were 6.7% (22 of 330 cases) in the ODD arms and 10.4% (34 of 327 cases) in the MDD arms. The fixed-effects risk ratio was 0.67 (95% CI: 0.42-1.07). The pooled microbiologic failure rates were 1.8% (5 of 283 cases) with ODD and 4.0% (11 of 275 cases) with MDD. The fixed-effects risk ratio was 0.51 (95% CI: 0.22-1.18). NEPHROTOXICITY: There was no significant difference between ODD and MDD in the primary nephrotoxicity outcomes. Secondary nephrotoxicity outcomes were significantly better with ODD. The pooled primary nephrotoxicity rates were 1.6% (15 of 955 cases) in the ODD arms and 1.6% (15 of 923 cases) in the MDD arms. The fixed-effects risk ratio was 0.97 (95% CI: 0.55-1.69). The pooled secondary nephrotoxicity rates were 4.4% (3 of 69 cases) in the ODD arms and 15.9% (11 of 69 cases) in the MDD arms, suggesting a statistically significant superiority of ODD. The fixed-effects risk ratio was 0.33 (95% CI: 0.12-0.89). Results were consistent across types of clinical settings and aminoglycosides. OTOTOXICITY: There was no significant difference between ODD and MDD in the primary ototoxicity outcomes. The pooled ototoxicity rates for studies that provided auditory testing results were 2.3% (10 of 436 cases) in the ODD arms and 2.0% (8 of 406 cases) in the MDD arms. The fixed-effects risk ratio was 1.06 (95% CI: 0.51-2.19). In studies that provided clinical vestibular function testing results, no toxicity was documented among 209 patients given ODD and 206 patients given MDD. Studies noting only the clinical impression of hearing impairment also failed to identify any toxicity (ODD: 114 cases; MDD: 114 cases). SUBGROUP AND BIAS ANALYSES: We detected no statistically significant differences between ODD and MDD in any of the examined subgroups (neonatal intensive care unit, cystic fibrosis, cancer, or urinary tract infection), with respect to combined clinical or microbiologic failure outcomes, primary nephrotoxicity outcomes, or ototoxicity (based on auditory testing), when sufficient data were available. Moreover, there was no significant relationship between the effect size (risk ratio) and the trial size for any of the outcomes. DATA INTERPRETATION: Clinical failures were uncommon in the pediatric trials, regardless of the regimen used. If anything, fewer clinical failures tended to occur with ODD. Moreover, we observed a trend toward decreased bacteriologic failures. One meta-analysis of adult data suggested that ODD might reduce nephrotoxicity, whereas other meta-analyses showed nonsignificant trends or no difference in nephrotoxicity outcomes. In our meta-analysis, we were not able to show any reduction in the risk of primary nephrotoxicity outcomes with ODD. However, the event rate was much lower among children, compared with adults, and the secondary nephrotoxicity outcomes favored ODD. Finally, although the 2 regimens seemed equivalent with respect to ototoxicity, reporting on ototoxicity outcomes was incomplete. Reassuringly, even in the trials that performed auditory testing, the rates of ototoxicity in the MDD arms were very low. These results were consistent with meta-analyses of adult data, which showed no difference in ototoxicity rates between ODD and MDD.Although single trials have been small, the available randomized evidence supports the general adoption of ODD of aminoglycosides in pediatric clinical practice. This approach minimizes cost, simplifies administration, and provides similar or even potentially improved efficacy and safety, compared with MDD of these drugs.

    View details for Web of Science ID 000222439200017

    View details for PubMedID 15231982

  • Effects of CCR5-Delta 32 and CCR2-64I alleles on disease progression of perinatally HIV-1-infected children: an international meta-analysis AIDS Ioannidis, J. P., Contopoulos-Ioannidis, D. G., Rosenberg, P. S., Goedert, J. J., De Rossi, A., Espanol, T., Frenkel, L., Mayaux, M. J., Newell, M. L., Pahwa, S. G., Rousseau, C., Scarlatti, G., Sei, S., Sen, L., O'Brien, T. R. 2003; 17 (11): 1631-1638


    Among perinatally infected children, the effects of certain alleles of the CCR5 and CCR2 genes on the rate of disease progression remain unclear. We addressed the effects of CCR5-delta32 and CCR2-64I in an international meta-analysis.Genotype data were contributed from 10 studies with 1317 HIV-1-infected children (7263 person-years of follow-up). Time-to-event analyses were performed stratified by study and racial group. Endpoints included progression to clinical AIDS, death, and death after the diagnosis of clinical AIDS. The time-dependence of the genetic effects was specifically investigated.There was large heterogeneity in the observed rates of disease progression between different cohorts. For progression to clinical AIDS, both CCR5-delta32 and CCR2-64I showed overall non-significant trends for protection [hazard ratios 0.84, 95% confidence interval (CI) 0.58-1.23; and 0.87, 95% CI 0.67-1.14, respectively]. However, analyses of survival showed statistically significant time-dependence. No deaths occurred among CCR5-delta32 carriers in the first 3 years of life, whereas there was no protective effect (hazard ratio 0.95; 95% CI 0.43-2.10) in later years (P=0.01 for the time-dependent model). For CCR2-64I, the hazard ratio for death was 0.69 (95% CI 0.39-1.21) in the first 6 years of life and 2.56 (95% CI 1.26-5.20) in subsequent years (P<0.01 for the time-dependent model). CCR5-delta32 and CCR2-64I offered no clear protection after clinical AIDS had developed.The CCR5-delta32 and CCR2-64I alleles are associated with a decreased risk of death among perinatally infected children, but only for the first years of life.

    View details for DOI 10.1097/01.aids.0000060411.18106.0f

    View details for Web of Science ID 000184661800007

    View details for PubMedID 12853745

  • Translation of highly promising basic science research into clinical applications AMERICAN JOURNAL OF MEDICINE Contopoulos-Ioannidis, D. G., Ntzani, E. E., Ioannidis, J. P. 2003; 114 (6): 477-484


    To evaluate the predictors of and time taken for the translation of highly promising basic research into clinical experimentation and use.We identified 101 articles, published between 1979 and 1983 in six major basic science journals, which clearly stated that the technology studied had novel therapeutic or preventive promises. Each case was evaluated for whether the promising finding resulted in relevant randomized controlled trials and clinical use. Main outcomes included the time to published trials, time to published trials with favorable results ("positive" trials), and licensed clinical use.By October 2002, 27 of the promising technologies had resulted in at least one published randomized trial, 19 of which had led to the publication of at least one positive randomized trial. Five basic science findings are currently licensed for clinical use, but only has been used extensively for the licensed indications. Promising technologies that did not lead to a published human study within 10 to 12 years were unlikely to be tested in humans subsequently. Some form of industry involvement in the basic science publication was the strongest predictor of clinical experimentation, accelerating the process by about eightfold (95% confidence interval: 3 to 19) when an author had industry affiliations.Even the most promising findings of basic research take a long time to translate into clinical experimentation, and adoption in clinical practice is rare.

    View details for DOI 10.1016/S0002-9343(03)00013-5

    View details for Web of Science ID 000182551900007

    View details for PubMedID 12731504

  • Genetic associations in large versus small studies: an empirical assessment LANCET Ioannidis, J. P., Trikalinos, T. A., Ntzani, E. E., Contopoulos-Ioannidis, D. G. 2003; 361 (9357): 567-571


    Advances in human genetics could help us to assess prognosis on an individual basis and to optimise the management of complex diseases. However, different studies on the same genetic association sometimes have discrepant results. Our aim was to assess how often large studies arrive at different conclusions than smaller studies, and whether this situation arises more frequently when findings of first published studies disagree with those of subsequent research.We examined the results of 55 meta-analyses (579 study comparisons) of genetic associations and tested whether the magnitude of the genetic effect differs in large versus smaller studies.We noted significant between-study heterogeneity in 26 (47%) meta-analyses. The magnitude of the genetic effect differed significantly in large versus smaller studies in ten (18%), 20 (36%), and 21 (38%) meta-analyses with tests of rank correlation, regression on SE, and regression on inverse of variance, respectively. The largest studies generally yielded more conservative results than the complete meta-analyses, which included all studies (p=0.005). In 14 (26%) meta-analyses the proposed association was significantly stronger in the first studies than in subsequent research. Only in nine (16%) meta-analyses was the genetic association significant and replicated without hints of heterogeneity or bias. There was little concordance in first versus subsequent discrepancies, and large versus small discrepancies.Genuine heterogeneity and bias could affect the results of genetic association studies. Genetic risk factors for complex diseases should be assessed cautiously and, if possible, using large scale evidence.

    View details for Web of Science ID 000181033400010

    View details for PubMedID 12598142

  • Acute sinusitis in children: current treatment strategies. Paediatric drugs Contopoulos-Ioannidis, D. G., Ioannidis, J. P., Lau, J. 2003; 5 (2): 71-80


    Acute sinusitis is a very common infection in childhood, but its management remains a controversial issue. Antibacterials may be effective in selected children, but direct evidence is limited. One randomized, placebo-controlled trial has shown that amoxicillin or amoxicillin/clavulanate are better than placebo for children with symptoms of nasal discharge and cough that are persistent (over 10 days) and not improving. However, another placebo-controlled trial of the same agents did not demonstrate any benefit from antibacterials in a patient population selected with a clinical diagnosis of sinusitis of moderate severity, based on a composite clinical symptom score. A systematic assessment of cure rates with various antibacterials shows no consistent differences between classes. Evidence on the use of ancillary measures and nasal corticosteroids is also limited. The only randomized, placebo-controlled trial of antihistamines and decongestants has shown no incremental benefit when given in addition to amoxicillin. Another placebo-controlled randomized trial showed some transient symptomatic improvement with the use of nasal corticosteroids. No randomized trials exist on the use of antral lavage in children with acute sinusitis. The current rates of antimicrobial resistance among commonly implicated pathogens should be considered in therapeutic decisions. However, there is no evidence from well-designed trials on specifically how to manage children at high risk of carrying resistant organisms. The inaccuracy of clinical signs and symptoms in documenting the diagnosis further complicates therapeutic decisions. Nevertheless, radiographic assessment does not meaningfully improve the accuracy of the diagnosis for uncomplicated cases, and it is not cost effective. In the absence of definitive evidence, treatment with amoxicillin 45 mg/kg/day in two divided doses may be used in selected patients with symptoms that are persistent and not improving. High doses (90 mg/kg in two divided doses) may also be considered, and amoxicillin/clavulanate may be a more appropriate choice when there is high risk of resistant pathogens, e.g. in a child attending a childcare center, or recent use of antibacterials. However, a considerable proportion of children, especially those with mild or improving symptoms, may not have to be treated at all.

    View details for PubMedID 12529160

  • Effect of CCR5-Delta 32 heterozygosity on the risk of perinatal HIV-1 infection: A meta-analysis JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Contopoulos-Ioannidis, D. G., O'Brien, T. R., Goedert, J. J., Rosenberg, P. S., Ioannidis, J. P. 2003; 32 (1): 70-76


    Several studies have investigated whether heterozygosity for a 32-basepair deletion in the CC chemokine receptor 5 gene (CCR5-Delta32 ) affects susceptibility to perinatal HIV-1 infection, but results have been inconclusive. We performed a meta-analysis of published data from 11 studies of HIV-1 perinatally exposed children who were genotyped for the CCR5-Delta32 polymorphism. The crude overall HIV-1 infection rates, by simple data pooling, were 20% (one of five) amongCCR5-Delta32 homozygote children, 39% (131 of 335) among CCR5-Delta32 heterozygote children, and 40% (1408 of 3526) among wild-type CCR5 homozygote children. Compared with wild-type homozygotes, the random effects risk ratio for heterozygotes was 1.04 (95% confidence interval [CI], 0.92-1.17) among all children (N = 3861) and 1.03 (95% CI, 0.90-1.17) among those of European descent (n = 2890). Results were similar when adjusted for the available data on the CCR2-641 polymorphism (n = 1542). The meta-analysis clarifies that perinatal infection is not significantly altered by heterozygosity for CCR5-Delta32 in the child.

    View details for Web of Science ID 000180407600010

    View details for PubMedID 12514416

  • Azithromycin is effective in patients with chronic bronchitis - Reply JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY Contopoulos-Ioannidis, D. G., Ioannidis, J. P., Lau, J. 2002; 50 (3): 434-434

    View details for DOI 10.1093/jac/dkf120

    View details for Web of Science ID 000177999000021

  • Citation of randomized evidence in support of guidelines of therapeutic and preventive interventions JOURNAL OF CLINICAL EPIDEMIOLOGY Giannakakis, I. A., Haidich, A. B., Contopoulos-Ioannidis, D. G., Papanikolaou, G. N., Baltogianni, M. S., Ioannidis, J. P. 2002; 55 (6): 545-555


    Guideline statements may be supported by evidence obtained from various study designs, but randomized trials are usually considered most important for making recommendations about therapeutic and preventive interventions. This study evaluated the extent to which randomized trials are cited in guidelines published in major journals. The references of 191 guidelines of therapeutic and/or preventive interventions published in Annals of Internal Medicine, BMJ, JAMA, Lancet, NEJM and Pediatrics in 1979, 1984, 1989, 1994, and 1999, were analyzed. The percentage of guidelines not citing any randomized controlled trials (RCTs) decreased gradually from 95% in 1979 to 53% in 1999. Among 4,853 references of the guidelines, there were 393 RCTs (8.1% of total), 19 systematic reviews (0.4%), and 23 meta-analyses of RCTs (0.5%). Among 19 guidelines published in 1999 or 1994 with <2 RCTs cited, in eight cases additional pertinent RCTs were identified that had not been cited by the guideline. There is a clear increase in the use of randomized evidence by guidelines over time. However, several guidelines in major journals still cite few or no RCTs.

    View details for Web of Science ID 000175958600002

    View details for PubMedID 12063096

  • Meta-analysis of randomized controlled trials on the comparative efficacy and safety of azithromycin against other antibiotics for upper respiratory tract infections JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY Ioannidis, J. P., Contopoulos-Ioannidis, D. G., Chew, P., Lau, J. 2001; 48 (5): 677-689


    We carried out a meta-analysis of randomized controlled trials comparing 3-5 days of azithromycin with other antibiotics that are typically given in longer courses for the treatment of upper respiratory tract infections. For acute otitis media (19 comparisons including 3421 patients), acute sinusitis (11 comparisons including 1742 patients) and acute pharyngitis (16 comparisons including 2447 patients), azithromycin had similar clinical failure rates to the other antibiotics [random effects odds ratios 1.12, 95% confidence interval (CI) 0.81-1.54; 0.91, 95% CI 0.60-1.39; and 1.07, 95% CI 0.59-1.94, respectively]. The difference in clinical failures was <0.5%, and no 95% CIs exceeded 2.0%. There was no heterogeneity between studies. Subtle differences between comparators could have been due to chance. There were no significant differences in bacteriological outcomes. Azithromycin was discontinued because of adverse events in only 37 of 4870 (0.8%) patients. Short courses of azithromycin are as effective as longer courses of other antibiotics for upper respiratory tract infections. Convenience of dosing should be balanced against the increased cost of this regimen for the treatment of these common infections, where often no antibiotic may be indicated at all.

    View details for Web of Science ID 000172342800011

    View details for PubMedID 11679557

  • Replication validity of genetic association studies NATURE GENETICS Ioannidis, J. P., Ntzani, E. E., Trikalinos, T. A., Contopoulos-Ioannidis, D. G. 2001; 29 (3): 306-309


    The rapid growth of human genetics creates countless opportunities for studies of disease association. Given the number of potentially identifiable genetic markers and the multitude of clinical outcomes to which these may be linked, the testing and validation of statistical hypotheses in genetic epidemiology is a task of unprecedented scale. Meta-analysis provides a quantitative approach for combining the results of various studies on the same topic, and for estimating and explaining their diversity. Here, we have evaluated by meta-analysis 370 studies addressing 36 genetic associations for various outcomes of disease. We show that significant between-study heterogeneity (diversity) is frequent, and that the results of the first study correlate only modestly with subsequent research on the same association. The first study often suggests a stronger genetic effect than is found by subsequent studies. Both bias and genuine population diversity might explain why early association studies tend to overestimate the disease protection or predisposition conferred by a genetic polymorphism. We conclude that a systematic meta-analytic approach may assist in estimating population-wide effects of genetic risk factors in human disease.

    View details for Web of Science ID 000171911000017

    View details for PubMedID 11600885

  • Comparison of evidence of treatment effects in randomized and nonrandomized studies JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Ioannidis, J. P., Haidich, A. B., Pappa, M., Pantazis, N., Kokori, S. I., Tektonidou, M. G., Contopoulos-Ioannidis, D. G., Lau, J. 2001; 286 (7): 821-830


    There is substantial debate about whether the results of nonrandomized studies are consistent with the results of randomized controlled trials on the same topic.To compare results of randomized and nonrandomized studies that evaluated medical interventions and to examine characteristics that may explain discrepancies between randomized and nonrandomized studies.MEDLINE (1966-March 2000), the Cochrane Library (Issue 3, 2000), and major journals were searched.Forty-five diverse topics were identified for which both randomized trials (n = 240) and nonrandomized studies (n = 168) had been performed and had been considered in meta-analyses of binary outcomes.Data on events per patient in each study arm and design and characteristics of each study considered in each meta-analysis were extracted and synthesized separately for randomized and nonrandomized studies.Very good correlation was observed between the summary odds ratios of randomized and nonrandomized studies (r = 0.75; P<.001); however, nonrandomized studies tended to show larger treatment effects (28 vs 11; P =.009). Between-study heterogeneity was frequent among randomized trials alone (23%) and very frequent among nonrandomized studies alone (41%). The summary results of the 2 types of designs differed beyond chance in 7 cases (16%). Discrepancies beyond chance were less common when only prospective studies were considered (8%). Occasional differences in sample size and timing of publication were also noted between discrepant randomized and nonrandomized studies. In 28 cases (62%), the natural logarithm of the odds ratio differed by at least 50%, and in 15 cases (33%), the odds ratio varied at least 2-fold between nonrandomized studies and randomized trials.Despite good correlation between randomized trials and nonrandomized studies-in particular, prospective studies-discrepancies beyond chance do occur and differences in estimated magnitude of treatment effect are very common.

    View details for Web of Science ID 000170429600030

    View details for PubMedID 11497536

  • Pathways for inappropriate dispensing of antibiotics for rhinosinusitis: A randomized trial CLINICAL INFECTIOUS DISEASES Contopoulos-Ioannidis, D. G., Koliofoti, I. D., Koutroumpa, I. C., Giannakakis, I. A., Ioannidis, J. P. 2001; 33 (1): 76-82


    We evaluated the extent of and factors that determine the inappropriate use of antibiotics that are obtained without a physician's prescription. Ninety-eight Greek pharmacists were visited by actress-researchers who played clients requesting antibiotics without a physician's prescription. Pharmacists were randomly challenged in a scenario that involved simulated cases of acute uncomplicated rhinosinusitis with either low fever (38.5 degrees C) or high fever (40 degrees C). Antibiotics were offered by 34 (69%) of 49 pharmacists who were presented with the high-fever scenario and by 42 (86%) of 49 pharmacists who were presented with the low-fever scenario (risk difference, 16.3%; P = .05). Thirty-two (65%) and 35 (71%) pharmacists in the high- and low-fever study arms, respectively, agreed to sell the actress-researchers broad-spectrum antibiotics. Only 28 (57%) and 17 (35%) pharmacists, respectively, recommended that the patient visit a physician (P = .03). Inappropriate recommendations regarding antibiotic use were very common in the studied setting. Antibiotics were more likely to be offered to persons who did not have a prescription when they were less likely to be clinically indicated.

    View details for Web of Science ID 000169101500019

    View details for PubMedID 11389498

  • The carboxyl terminus of the human cytomegalovirus UL37 immediate-early glycoprotein is conserved in primary strains and is important for transactivation JOURNAL OF GENERAL VIROLOGY Hayajneh, W. A., Contopoulos-Ioannidis, D. G., Lesperance, M. M., Venegas, A. M., Colberg-Poley, A. M. 2001; 82: 1569-1579


    The human cytomegalovirus (HCMV) UL37 exon 3 (UL37x3) open reading frame (ORF) encodes the carboxyl termini of two immediate-early glycoproteins (gpUL37 and gpUL37(M)). UL37x3 homologous sequences are not required for mouse cytomegalovirus (MCMV) growth in vitro; yet, they are important for MCMV growth and pathogenesis in vivo. Similarly, UL37x3 sequences are dispensable for HCMV growth in culture, but their requirement for HCMV growth in vivo is not known. To determine this requirement, we directly sequenced the complete UL37x3 gene in multiple HCMV primary strains. A total of 63 of the 310 amino acids in the UL37x3 ORF differ non-conservatively in one or more HCMV primary strains. The HCMV UL37x3 genetic diversity is non-random: the N-glycosylation (46/186 aa) and basic (9/15 aa) domains have the highest proportion of non-conservative variant amino acids. Nonetheless, most (15/17 signals) of the N-glycosylation signals are retained in all HCMV primary strains. Moreover, new N-glycosylation signals are encoded by 5/20 primary strains. In sharp contrast, the UL37x3 transmembrane (TM) ORF completely lacks diversity in all 20 HCMV sequenced primary strains, and only 1 of 28 cytosolic tail residues differs non-conservatively. To test the functional significance of the conserved carboxyl terminus, gpUL37 mutants lacking the TM and/or cytosolic tail were tested for transactivating activity. The gpUL37 carboxyl-terminal mutants are partially defective in hsp70 promoter transactivation even though they trafficked similarly to the wild-type protein into the endoplasmic reticulum and to mitochondria. From these results, we conclude that N-glycosylated gpUL37, particularly its TM and cytosolic domains, is important for HCMV growth in humans.

    View details for Web of Science ID 000169435800005

    View details for PubMedID 11413367

  • The sequence and antiapoptotic functional domains of the human cytomegalovirus UL37 exon 1 immediate early protein are conserved in multiple primary strains VIROLOGY Hayajneh, W. A., Colberg-Poley, A. M., Skaletskaya, A., Bartle, L. M., Lesperance, M. M., Contopoulos-Ioannidis, D. G., Kedersha, N. L., Goldmacher, V. S. 2001; 279 (1): 233-240


    The human cytomegalovirus UL37 exon 1 gene encodes the immediate early protein pUL37x1 that has antiapoptotic and regulatory activities. Deletion mutagenesis analysis of the open reading frame of UL37x1 identified two domains that are necessary and sufficient for its antiapoptotic activity. These domains are confined within the segments between amino acids 5 to 34, and 118 to 147, respectively. The first domain provides the targeting of the protein to mitochondria. Direct PCR sequencing of UL37 exon 1 amplified from 26 primary strains of human cytomegalovirus demonstrated that the promoter, polyadenylation signal, and the two segments of pUL37x1 required for its antiapoptotic function were invariant in all sequenced strains and identical to those in AD169 pUL37x1. In total, UL37 exon 1 varies between 0.0 and 1.6% at the nucleotide level from strain AD169. Only 11 amino acids were found to vary in one or more viral strains, and these variations occurred only in the domains of pUL37x1 dispensable for its antiapoptotic function. We infer from this remarkable conservation of pUL37x1 in primary strains that this protein and, probably, its antiapoptotic function are required for productive replication of human cytomegalovirus in humans.

    View details for Web of Science ID 000166516300023

    View details for PubMedID 11145905

  • Reporting of conflicts of interest in guidelines of preventive and therapeutic interventions. BMC medical research methodology Papanikolaou, G. N., Baltogianni, M. S., Contopoulos-Ioannidis, D. G., Haidich, A. B., Giannakakis, I. A., Ioannidis, J. P. 2001; 1: 3-?


    Guidelines published in major medical journals are very influential in determining clinical practice. It would be essential to evaluate whether conflicts of interests are disclosed in these publications. We evaluated the reporting of conflicts of interest and the factors that may affect such disclosure in a sample of 191 guidelines on therapeutic and/or preventive measures published in 6 major clinical journals (Annals of Internal Medicine, BMJ, JAMA, Lancet, New England Journal of Medicine, Pediatrics) in 1979, 1984, 1989, 1994 and 1999.Only 7 guidelines (3.7%) mentioned conflicts of interest and all were published in 1999 (17.5% (7/40) of guidelines published in 1999 alone). Reporting of conflicts of interest differed significantly by journal (p=0.026), availability of disclosure policy by the journal (p=0.043), source of funding (p < 0.001) and number of authors (p=0.004). In the entire database of 191 guidelines, a mere 18 authors disclosed a total of 24 potential conflicts of interest and most pertained to minor issues.Despite some recent improvement, reporting of conflicts of interest in clinical guidelines published in influential journals is largely neglected.

    View details for PubMedID 11405896

    View details for PubMedCentralID PMC32303

  • Maternal viral load and the risk of perinatal transmission of HIV-1 NEW ENGLAND JOURNAL OF MEDICINE Ioannidis, J. P., Contopoulos-Ioannidis, D. G. 1999; 341 (22): 1698-1699

    View details for Web of Science ID 000083847500017

    View details for PubMedID 10610439

  • Predictors and impact of losses to follow-up in an HIV-1 perinatal transmission cohort in Malawi INTERNATIONAL JOURNAL OF EPIDEMIOLOGY Ioannidis, J. P., Taha, T. E., Kumwenda, N., Broadhead, R., Mtimavalye, L., Miotti, P., Yellin, F., Contopoulos-Ioannidis, D. G., Biggar, R. J. 1999; 28 (4): 769-775


    Large simple trials which aim to study therapeutic interventions and epidemiological associations of human immunodeficiency virus (HIV) infection, including perinatal transmission, in Africa may have substantial rates of loss to follow-up. A better understanding of the characteristics and the impact of women and children lost to follow-up is needed.We studied predictors and the impact of losses to follow-up of infants born in a large cohort of delivering women in urban Malawi. The cohort was established as part of a trial of vaginal cleansing with chlorhexidine during delivery to prevent mother-to-infant transmission of HIV.The HIV infection status could not be determined for 797 (36.9%) of 2156 infants born to HIV-infected mothers; 144 (6.7%) with missing status because of various sample problems and 653 (30.3%) because they never returned to the clinic. Notably, the observed rates of perinatal transmission were significantly lower in infants who returned later for determination of their infection status (odds ratio = 0.94 per month, P = 0.03), even though these infants must have had an additional risk of infection from breastfeeding. In multivariate models, infants of lower birthweight (P = 0.003) and, marginally, singletons (P = 0.09) were less likely to return for follow-up. The parents of infants lost to follow-up tended to be less educated (P < 0.001) and more likely to be in farming occupations, although one educated group, teachers and students, were also significantly less likely to return. Of these variables, infant birthweight, twins versus singletons, and maternal education were also associated with significant variation in the observed risk of perinatal transmission among infants of known HIV status.Several predictors of loss to follow-up were identified in this large HIV perinatal cohort. Losses to follow-up can impact the observed transmission rate and the risk associations in different studies.

    View details for Web of Science ID 000082344000026

    View details for PubMedID 10480709

  • Recursive cumulative meta-analysis: A diagnostic for the evolution of total randomized evidence from group and individual patient data JOURNAL OF CLINICAL EPIDEMIOLOGY Ioannidis, J. P., Contopoulos-Ioannidis, D. G., Lau, J. 1999; 52 (4): 281-291


    Meta-analyses of randomized evidence may include published, unpublished, and updated data in an ongoing estimation process that continuously accommodates more data. Synthesis may be performed either with group data or with meta-analysis of individual patient data (MIPD). Although MIPD with updated data is considered the gold standard of evidence, there is a need for a careful study of the impact different sources of data have on a meta-analysis and of the change in the treatment effect estimates over sequential information steps. Unpublished data and late-appearing data may be different from early-appearing data. Updated information after the end of the main study follow-up may be affected by cross-overs, missing information, and unblinding. The estimated treatment effect may thus depend on the completeness and updating of the available evidence. To address these issues, we present recursive cumulative meta-analysis (RCM) as an extension of cumulative metaanalysis. Recursive cumulative meta-analysis is based on the principle of recalculating the results of a cumulative meta-analysis with each new or updated piece of information and focuses on the evolution of the treatment effect as a more complete and updated picture of the evidence becomes available. An examination of the perturbations of the cumulative treatment effect over sequential information steps may signal the presence of bias or heterogeneity in a meta-analysis. Recursive cumulative meta-analysis may suggest whether there is a true underlying treatment effect to which the meta-analysis is converging and how treatment effects are sequentially altered by new or modified evidence. The method is illustrated with an example from the conduct of an MIPD on acyclovir in human immunodeficiency virus infection. The relative strengths and limitations of both metaanalysis of group data and MIPD are discussed through the RCM perspective.

    View details for Web of Science ID 000080058300002

    View details for PubMedID 10235168

  • Reporting of safety data from randomised trials LANCET Ioannidis, J. P., Contopoulos-Ioannidis, D. G. 1998; 352 (9142): 1752-1753

    View details for Web of Science ID 000077246500014

    View details for PubMedID 9848355

  • Clinical efficacy of high-dose acyclovir in patients with human immunodeficiency virus infection: A meta-analysis of randomized individual patient data 5th Conference on Retroviruses and Opportunistic Infections Ioannidis, J. P., Collier, A. C., Cooper, D. A., Corey, L., FIDDIAN, A. P., Gazzard, B. G., Griffiths, P. D., Contopoulos-Ioannidis, D. G., Lau, J., Pavia, A. T., Saag, M. S., Spruance, S. L., Youle, M. S. UNIV CHICAGO PRESS. 1998: 349–59


    A meta-analysis of 8 randomized trials (1792 patients, 2947 patient-years of follow-up) showed that acyclovir (> or = 3200 mg/day) offered a significant survival benefit (P = .006 by log-rank test) in human immunodeficiency virus (HIV) infection. The treatment effect did not vary significantly in patient subgroups of different CD4 cell counts, hemoglobin levels, age, race, and sex, and with or without AIDS diagnosis. Acyclovir treatment (hazard ratio, 0.78; 95% confidence interval [CI], 0.65-0.93), higher CD4 cell count (P < .001), higher hemoglobin level (P < .001), and younger age (P < .001) reduced the hazard of mortality. Acyclovir decreased herpes simplex virus infections (odds ratio [OR], 0.28; 95% CI, 0.21-0.37) and varicella-zoster virus infections (OR, 0.29; 95% CI, 0.13-0.63) but not cytomegalovirus disease or mortality from lymphoma or Kaposi's sarcoma. A survival advantage was seen specifically in studies with high incidence of clinical herpesvirus infections (> or = 25% per year). Given the wide confidence intervals, the small effect in low-risk patients, and recent changes in HIV therapeutics, the results should be interpreted cautiously, but the meta-analysis supports the importance of pathogenetic interactions between herpesviruses and HIV.

    View details for Web of Science ID 000075153000009

    View details for PubMedID 9697714

  • Maternal cell-free viremia in the natural history of perinatal HIV-1 transmission - A meta-analysis JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Contopoulos-Ioannidis, D. G., Ioannidis, J. P. 1998; 18 (2): 126-135


    We performed a meta-analysis of the predictive value of maternal cell-free viral load in vertical HIV-1 transmission, including 9 cohorts with 1115 mother-infant pairs (696 untreated and 419 treated women). The pooled rate of transmission in untreated women was 21.3% (95% confidence interval [CI], 18.3%-24.5%). The rates of transmission for untreated women in the <1000 copies/ml, 1000 to 9999 copies/ml, and > or = 10,000 copies/ml categories were 5% (95% CI, 2%-11%), 15% (95% CI, 11%-20%) and 37% (95% CI, 29%-46% by random effects), respectively. The area under the receiver operating characteristic (ROC) curve in individual studies ranged from 0.67 to 1.00. The predictive performance of RNA differed between cohorts in which different percentages of transmitters had RNA values >10,000 copies/ml. When 95% of transmitters have RNA values >1000 copies/ml, 77% of nontransmitters would also have values above this cutoff. Transmission rates for treated women in the 1000 to 9999 copies/ml category (7%; 95% CI, 4%-11%,) and > or = 10,000 copies/ml category (18%; 95% CI, 12%-27%) were probably lower than those for untreated women, whereas the transmission rate for treated women with <1000 copies/ml was 5% (95% CI, 2%-11 %). Thus, the risk gradient between RNA categories seems attenuated in treated women. Several aspects of the design, analysis, and reporting of research in this area may be improved in the future with attention to selection and observer biases, multivariate adjustment, and technical consistency. Maternal HIV-1 RNA is a modest predictor of transmission for individual mothers, but a strong predictor of the average risk in groups of untreated mothers. Its discriminatory power is better in untreated than in treated populations and is better in cohorts with a high prevalence of elevated viral load values than in cohorts with generally low levels of viremia.

    View details for Web of Science ID 000074168900004

    View details for PubMedID 9637577

  • Genetic effects on HIV disease progression NATURE MEDICINE Ioannidis, J. P., O'Brien, T. R., Rosenberg, P. S., Contopoulos-Ioannidis, D. G., Goedert, J. J. 1998; 4 (5): 536-536

    View details for Web of Science ID 000073399900002

    View details for PubMedID 9585207

  • PCR detection of human cytomegalovirus DNA in clinical specimens using novel UL37 exon 3 and US3 primers CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY Lesperance, M. M., Contopoulos-Ioannidis, D. G., Gutierrez, M. D., Colberg-Poley, A. M. 1998; 5 (2): 256-258


    The sensitivity and specificity of novel UL37 exon 3 (UL37x3) and US3 immediate-early (IE) gene PCR primers to detect human cytomegalovirus (HCMV) DNA in clinical specimens are comparable to those of HCMV DNA polymerase (UL54) primers. The use of these IE primers increases the diagnostic performance of HCMV PCR.

    View details for Web of Science ID 000072405600023

    View details for PubMedID 9521154