Affiliation:
1. Department of Mathematics, College of Big Data and Internet Shenzhen Technology University Shenzhen People's Republic of China
2. Department of Applied Statistics Konkuk University Seoul Republic of Korea
3. Department of Biostatistics Yale University School of Public Health New Haven Connecticut USA
4. Center for Methods in Implementation and Prevention Science Yale University School of Public Health New Haven Connecticut USA
Abstract
AbstractWhen the distributions of treatment effect modifiers differ between a randomized trial and an external target population, the sample average treatment effect in the trial may be substantially different from the target population average treatment, and accurate estimation of the latter requires adjusting for the differential distribution of effect modifiers. Despite the increasingly rich literature on transportability, little attention has been devoted to methods for transporting trial results to estimate counterfactual survival functions in target populations, when the primary outcome is time to event and subject to right censoring. In this article, we study inverse probability weighting and doubly robust estimators to estimate counterfactual survival functions and the target average survival treatment effect in the target population, and provide their respective approximate variance estimators. We focus on a common scenario where the target population information is observed only through a complex survey, and elucidate how the survey weights can be incorporated into each estimator we considered. Simulation studies are conducted to examine the finite‐sample performances of the proposed estimators in terms of bias, efficiency and coverage, under both correct and incorrect model specifications. Finally, we apply the proposed method to assess transportability of the results in the Action to Control Cardiovascular Risk in Diabetes—Blood Pressure (ACCORD‐BP) trial to all adults with Diabetes in the United States.
Funder
National Center for Advancing Translational Sciences
Subject
Pharmacology (medical),Pharmacology,Statistics and Probability