Erik Sverdrup

All Publications

• Low-intensity fires mitigate the risk of high-intensity wildfires in California's forests. Science advances Wu, X., Sverdrup, E., Mastrandrea, M. D., Wara, M. W., Wager, S. 2023; 9 (45): eadi4123

  Abstract

  The increasing frequency of severe wildfires demands a shift in landscape management to mitigate their consequences. The role of managed, low-intensity fire as a driver of beneficial fuel treatment in fire-adapted ecosystems has drawn interest in both scientific and policy venues. Using a synthetic control approach to analyze 20 years of satellite-based fire activity data across 124,186 square kilometers of forests in California, we provide evidence that low-intensity fires substantially reduce the risk of future high-intensity fires. In conifer forests, the risk of high-intensity fire is reduced by 64.0% [95% confidence interval (CI): 41.2 to 77.9%] in areas recently burned at low intensity relative to comparable unburned areas, and protective effects last for at least 6 years (lower bound of one-sided 95% CI: 6 years). These findings support a policy transition from fire suppression to restoration, through increased use of prescribed fire, cultural burning, and managed wildfire, of a presuppression and precolonial fire regime in California.

  View details for DOI 10.1126/sciadv.adi4123

  View details for PubMedID 37948522

  View details for PubMedCentralID PMC10637742

• Estimated Average Treatment Effect of Psychiatric Hospitalization in Patients With Suicidal Behaviors: A Precision Treatment Analysis. JAMA psychiatry Ross, E. L., Bossarte, R. M., Dobscha, S. K., Gildea, S. M., Hwang, I., Kennedy, C. J., Liu, H., Luedtke, A., Marx, B. P., Nock, M. K., Petukhova, M. V., Sampson, N. A., Zainal, N. H., Sverdrup, E., Wager, S., Kessler, R. C. 2023

  Abstract

  Psychiatric hospitalization is the standard of care for patients presenting to an emergency department (ED) or urgent care (UC) with high suicide risk. However, the effect of hospitalization in reducing subsequent suicidal behaviors is poorly understood and likely heterogeneous.To estimate the association of psychiatric hospitalization with subsequent suicidal behaviors using observational data and develop a preliminary predictive analytics individualized treatment rule accounting for heterogeneity in this association across patients.A machine learning analysis of retrospective data was conducted. All veterans presenting with suicidal ideation (SI) or suicide attempt (SA) from January 1, 2010, to December 31, 2015, were included. Data were analyzed from September 1, 2022, to March 10, 2023. Subgroups were defined by primary psychiatric diagnosis (nonaffective psychosis, bipolar disorder, major depressive disorder, and other) and suicidality (SI only, SA in past 2-7 days, and SA in past day). Models were trained in 70.0% of the training samples and tested in the remaining 30.0%.Psychiatric hospitalization vs nonhospitalization.Fatal and nonfatal SAs within 12 months of ED/UC visits were identified in administrative records and the National Death Index. Baseline covariates were drawn from electronic health records and geospatial databases.Of 196 610 visits (90.3% men; median [IQR] age, 53 [41-59] years), 71.5% resulted in hospitalization. The 12-month SA risk was 11.9% with hospitalization and 12.0% with nonhospitalization (difference, -0.1%; 95% CI, -0.4% to 0.2%). In patients with SI only or SA in the past 2 to 7 days, most hospitalization was not associated with subsequent SAs. For patients with SA in the past day, hospitalization was associated with risk reductions ranging from -6.9% to -9.6% across diagnoses. Accounting for heterogeneity, hospitalization was associated with reduced risk of subsequent SAs in 28.1% of the patients and increased risk in 24.0%. An individualized treatment rule based on these associations may reduce SAs by 16.0% and hospitalizations by 13.0% compared with current rates.The findings of this study suggest that psychiatric hospitalization is associated with reduced average SA risk in the immediate aftermath of an SA but not after other recent SAs or SI only. Substantial heterogeneity exists in these associations across patients. An individualized treatment rule accounting for this heterogeneity could both reduce SAs and avert hospitalizations.

  View details for DOI 10.1001/jamapsychiatry.2023.3994

  View details for PubMedID 37851457

  View details for PubMedCentralID PMC10585585

• Estimating heterogeneous treatment effects with right-censored data via causal survival forests JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES B-STATISTICAL METHODOLOGY Cui, Y., Kosorok, M. R., Sverdrup, E., Wager, S., Zhu, R. 2023

  View details for DOI 10.1093/jrsssb/qkac001

  View details for Web of Science ID 000939480100001

• DOUBLY ROBUST TREATMENT EFFECT ESTIMATION WITH MISSING ATTRIBUTES ANNALS OF APPLIED STATISTICS Mayer, I., Sverdrup, E., Gauss, T., Moyer, J., Wager, S., Josse, J. 2020; 14 (3): 1409–31

  View details for DOI 10.1214/20-AOAS1356

  View details for Web of Science ID 000573263200016