A1292
Title: Estimating time-varying treatment effects on restricted mean survival time in large patient databases
Authors: Chi Hyun Lee - University of Massachusetts Amherst (United States) [presenting]
Abstract: The restricted mean survival time (RMST), defined as the life expectancy up to a specific point, has recently attracted substantial attention as an alternative to the hazard ratio for quantifying the treatment effect in clinical studies. A flexible model is proposed to estimate the effect of treatment based on RMST. The effect of treatment is expressed as a function of restriction time better to characterize the dynamic trend of its effect on survivall. To account for possible heterogeneity across patients in large databases, the propensity scores are incorporated for receiving treatment into the model. Further, an ensemble approach is introduced to aggregate estimators constructed based on subsamples of the observed failure times. The finite sample performance of the proposed single model and ensemble-based approaches through simulations are evaluated, and the proposed methods are applied to the study of primary inflammatory breast cancer for assessing the effect of trimodality therapy on survival.