Brand versus generic: addressing non-adherence, secular trends and non-overlap

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

doi:10.1111/rssa.12573

Brand versus generic: addressing non-adherence, secular trends and non-overlap

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

Research output: Contribution to journal › Article › peer-review

Abstract

Whereas 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 venlafaxine, based on a large insurance claims data set provided by OptumLabs^\circledR. To address this question properly, 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 drug 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 immediate release venlafaxine.

Original language	English (US)
Pages (from-to)	1461-1478
Number of pages	18
Journal	Journal of the Royal Statistical Society. Series A: Statistics in Society
Volume	183
Issue number	4
DOIs	https://doi.org/10.1111/rssa.12573
State	Published - Oct 1 2020

Keywords

G-computation
Generic drugs
Regression discontinuity
Temporal confounding
Therapeutic equivalence
Time-varying confounding
Venlafaxine

ASJC Scopus subject areas

Statistics and Probability
Social Sciences (miscellaneous)
Economics and Econometrics
Statistics, Probability and Uncertainty

Access to Document

10.1111/rssa.12573

Cite this

@article{b1b6252a4de0447583a9f7e6efc1cbf5,

title = "Brand versus generic: addressing non-adherence, secular trends and non-overlap",

abstract = "Whereas 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 venlafaxine, based on a large insurance claims data set provided by OptumLabs\circledR. To address this question properly, 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 drug 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 immediate release venlafaxine.",

keywords = "G-computation, Generic drugs, Regression discontinuity, Temporal confounding, Therapeutic equivalence, Time-varying confounding, Venlafaxine",

author = "Lamar Hunt and Murimi, {Irene B} and Segal, {Jodi B.} and Seamans, {Marissa J.} and Scharfstein, {Daniel O.} and Ravi Varadhan",

note = "Funding Information: We thank Ramin Mojtabai for providing his medical expertise, Vijay S. Nori for aiding in the computation, Michael A. Rosenblum and Ilya Shpitser for providing their insight on how to think about the problem from a causal inference perspective, and OptumLabs. Funding for this paper was made possible, in part, by the Food and Drug Administration through grant 1U01FD005556-01. Views expressed in the paper do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organizations imply endorsement by the US Government. Funding Information: Funding for this paper was made possible, in part, by the Food and Drug Administration through grant 1U01FD005556‐01. Views expressed in the paper do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organizations imply endorsement by the US Government. Publisher Copyright: {\textcopyright} 2020 Royal Statistical Society",

year = "2020",

month = oct,

day = "1",

doi = "10.1111/rssa.12573",

language = "English (US)",

volume = "183",

pages = "1461--1478",

journal = "Journal of the Royal Statistical Society. Series A: Statistics in Society",

issn = "0964-1998",

publisher = "Wiley-Blackwell",

number = "4",

}

TY - JOUR

T1 - Brand versus generic

T2 - addressing non-adherence, secular trends and non-overlap

AU - Hunt, Lamar

AU - Murimi, Irene B

AU - Segal, Jodi B.

AU - Seamans, Marissa J.

AU - Scharfstein, Daniel O.

AU - Varadhan, Ravi

N1 - Funding Information: We thank Ramin Mojtabai for providing his medical expertise, Vijay S. Nori for aiding in the computation, Michael A. Rosenblum and Ilya Shpitser for providing their insight on how to think about the problem from a causal inference perspective, and OptumLabs. Funding for this paper was made possible, in part, by the Food and Drug Administration through grant 1U01FD005556-01. Views expressed in the paper do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organizations imply endorsement by the US Government. Funding Information: Funding for this paper was made possible, in part, by the Food and Drug Administration through grant 1U01FD005556‐01. Views expressed in the paper do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organizations imply endorsement by the US Government. Publisher Copyright: © 2020 Royal Statistical Society

PY - 2020/10/1

Y1 - 2020/10/1

N2 - Whereas 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 venlafaxine, based on a large insurance claims data set provided by OptumLabs\circledR. To address this question properly, 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 drug 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 immediate release venlafaxine.

AB - Whereas 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 venlafaxine, based on a large insurance claims data set provided by OptumLabs\circledR. To address this question properly, 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 drug 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 immediate release venlafaxine.

KW - G-computation

KW - Generic drugs

KW - Regression discontinuity

KW - Temporal confounding

KW - Therapeutic equivalence

KW - Time-varying confounding

KW - Venlafaxine

UR - http://www.scopus.com/inward/record.url?scp=85084987977&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85084987977&partnerID=8YFLogxK

U2 - 10.1111/rssa.12573

DO - 10.1111/rssa.12573

M3 - Article

AN - SCOPUS:85084987977

SN - 0964-1998

VL - 183

SP - 1461

EP - 1478

JO - Journal of the Royal Statistical Society. Series A: Statistics in Society

JF - Journal of the Royal Statistical Society. Series A: Statistics in Society

IS - 4

ER -

Brand versus generic: addressing non-adherence, secular trends and non-overlap

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this