TY - JOUR
T1 - A tutorial on individualized treatment effect prediction from randomized trials with a binary endpoint
AU - Hoogland, Jeroen
AU - IntHout, Joanna
AU - Belias, Michail
AU - Rovers, Maroeska M.
AU - Riley, Richard D.
AU - e. Harrell Jr, Frank
AU - Moons, Karel G. M.
AU - Debray, Thomas P. A.
AU - Reitsma, Johannes B.
N1 - Funding Information: Jeroen Hoogland, Michail Belias, Joanna IntHout, Maroeska M. Rovers, Thomas P. A. Debray and Johannes B. Reitsma acknowledge financial support from the Netherlands Organisation for Health Research and Development (grant 91215058). Thomas P. A. Debray also acknowledges financial support from the Netherlands Organisation for Health Research and Development (grant 91617050) Publisher Copyright: © 2021 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.
PY - 2021/11/20
Y1 - 2021/11/20
N2 - Randomized trials typically estimate average relative treatment effects, but decisions on the benefit of a treatment are possibly better informed by more individualized predictions of the absolute treatment effect. In case of a binary outcome, these predictions of absolute individualized treatment effect require knowledge of the individual's risk without treatment and incorporation of a possibly differential treatment effect (ie, varying with patient characteristics). In this article, we lay out the causal structure of individualized treatment effect in terms of potential outcomes and describe the required assumptions that underlie a causal interpretation of its prediction. Subsequently, we describe regression models and model estimation techniques that can be used to move from average to more individualized treatment effect predictions. We focus mainly on logistic regression-based methods that are both well-known and naturally provide the required probabilistic estimates. We incorporate key components from both causal inference and prediction research to arrive at individualized treatment effect predictions. While the separate components are well known, their successful amalgamation is very much an ongoing field of research. We cut the problem down to its essentials in the setting of a randomized trial, discuss the importance of a clear definition of the estimand of interest, provide insight into the required assumptions, and give guidance with respect to modeling and estimation options. Simulated data illustrate the potential of different modeling options across scenarios that vary both average treatment effect and treatment effect heterogeneity. Two applied examples illustrate individualized treatment effect prediction in randomized trial data.
AB - Randomized trials typically estimate average relative treatment effects, but decisions on the benefit of a treatment are possibly better informed by more individualized predictions of the absolute treatment effect. In case of a binary outcome, these predictions of absolute individualized treatment effect require knowledge of the individual's risk without treatment and incorporation of a possibly differential treatment effect (ie, varying with patient characteristics). In this article, we lay out the causal structure of individualized treatment effect in terms of potential outcomes and describe the required assumptions that underlie a causal interpretation of its prediction. Subsequently, we describe regression models and model estimation techniques that can be used to move from average to more individualized treatment effect predictions. We focus mainly on logistic regression-based methods that are both well-known and naturally provide the required probabilistic estimates. We incorporate key components from both causal inference and prediction research to arrive at individualized treatment effect predictions. While the separate components are well known, their successful amalgamation is very much an ongoing field of research. We cut the problem down to its essentials in the setting of a randomized trial, discuss the importance of a clear definition of the estimand of interest, provide insight into the required assumptions, and give guidance with respect to modeling and estimation options. Simulated data illustrate the potential of different modeling options across scenarios that vary both average treatment effect and treatment effect heterogeneity. Two applied examples illustrate individualized treatment effect prediction in randomized trial data.
KW - causal inference
KW - personalized medicine
KW - prediction
KW - regression
KW - treatment effect
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85112796808&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/34402094
UR - http://www.scopus.com/inward/record.url?scp=85112796808&partnerID=8YFLogxK
U2 - https://doi.org/10.1002/sim.9154
DO - https://doi.org/10.1002/sim.9154
M3 - Article
C2 - 34402094
SN - 0277-6715
VL - 40
SP - 5961
EP - 5981
JO - Statistics in medicine
JF - Statistics in medicine
IS - 26
ER -