Brand vs. Generic: Addressing Non-Adherence, Secular Trends, and Non-Overlap
Abstract
While generic drugs offer a cost-effective alternative to brand name drugs, regulators need a method to assess therapeutic equivalence in a post market setting. We develop such a method in the context of assessing the therapeutic equivalence of immediate release (IM) venlafaxine, based on a large insurance claims dataset provided by OptumLabs\textsuperscript{\textregistered}. To properly address this question, our methodology must deal with issues of non-adherence, secular trends in health outcomes, and lack of treatment overlap due to sharp uptake of the generic once it becomes available. We define, identify (under assumptions) and estimate (using G-computation) a causal effect for a time-to-event outcome by extending regression discontinuity to survival curves. We do not find evidence for a lack of therapeutic equivalence of brand and generic IM venlafaxine.
Cite
@article{arxiv.1907.05385,
title = {Brand vs. Generic: Addressing Non-Adherence, Secular Trends, and Non-Overlap},
author = {Lamar Hunt and Irene B. Murimi and Jodi B. Segal and Marissa J. Seamans and Daniel O. Scharfstein and Ravi Varadhan},
journal= {arXiv preprint arXiv:1907.05385},
year = {2019}
}