3 papers
stat.ME2026
Improving the efficiency of infectious disease prevention trials using negative control outcome event times
Ethan Ashby, Zhewei Zhang, Tanya P. Garcia +3
Baseline covariate adjustment can enhance the efficiency of randomized trials by improving precision of treatment effect estimates. However, the precision gain depends on how stron…
stat.ME2025
Debiasing hazard-based, time-varying vaccine effects using vaccine-irrelevant infections: An observational extension of a pivotal Phase 3 COVID-19 vaccine efficacy trial
Ethan Ashby, Dean Follmann, Holly Janes +5
Understanding how vaccine effectiveness (VE) changes over time can provide evidence-based guidance for public health decision making. While commonly reported by practitioners, time…
stat.ME2025
Negative Control Outcome Adjustment in Early-Phase Randomized Trials: Estimating Vaccine Effects on Immune Responses in HIV Exposed Uninfected Infants
Ethan Ashby, Bo Zhang, Genevieve G Fouda +2
Adjustment for prognostic baseline variables can reduce bias due to covariate imbalance and increase efficiency in randomized trials. While the use of covariate adjustment in late-…