Online Program

WITHDRAWN: Propensity Score Methods in Comparaive Effectiveness Study of Multiple Treatments

Bassam Dahman, Virginia Commonwealth University 

Keywords: propensity score, multiple treatments, simulation, comparative effectiveness

The propensity score (PS) methods are commonly used now in observational studies. Health policy researchers utilize these methods to adjust for the confounding problems and reduce the bias in estimating the treatment effects that result from the non-random allocation of treatments in observational studies. A few PS methods are developed to estimate the treatment effects in the presence of more than two treatment groups. These include using PS as covariates or weights, or using them in matching. This paper reviews these methods, and describes the challenges in i) estimating the PS using different multinomial models ii) using these PS in matching iii) utilizing the different methods of using PS to adjusting for confounding. These methods were applied and compared in a comparative effectiveness study of the different treatments of newly diagnosed prostate cancer patients. Simulation studies built on the data extracted from SEER linked Medicare database were used to evaluate the properties of the different PS methods and to compare the estimates the treatment effects.