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arXiv · 1907.05385

Brand vs. Generic: Addressing Non-Adherence, Secular Trends, and Non-Overlap

Lamar Hunt III·Irene B. Murimi·Jodi B. Segal·Marissa J. Seamans·Daniel O. Scharfstein·Ravi Varadhan
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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.

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Lamar Hunt III, Irene B. Murimi, Jodi B. Segal, Marissa J. Seamans, Daniel O. Scharfstein, Ravi Varadhan. 2019-07-07. Brand vs. Generic: Addressing Non-Adherence, Secular Trends, and Non-Overlap. https://arxiv.org/abs/1907.05385

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