Lifetime Data Analysis

, Volume 19, Issue 2, pp 219–241 | Cite as

Semiparametric inference on the absolute risk reduction and the restricted mean survival difference

Article

Abstract

For time-to-event data, when the hazards are non-proportional, in addition to the hazard ratio, the absolute risk reduction and the restricted mean survival difference can be used to describe the time-dependent treatment effect. The absolute risk reduction measures the direct impact of the treatment on event rate or survival, and the restricted mean survival difference provides a way to evaluate the cumulative treatment effect. However, in the literature, available methods are limited for flexibly estimating these measures and making inference on them. In this article, point estimates, pointwise confidence intervals and simultaneous confidence bands of the absolute risk reduction and the restricted mean survival difference are established under a semiparametric model that can be used in a sufficiently wide range of applications. These methods are motivated by and illustrated for data from the Women’s Health Initiative estrogen plus progestin clinical trial.

Keywords

Absolute risk reduction Clinical trial Non-proportional hazards Restricted mean survival Semiparametric analysis Simultaneous inference 

Notes

Acknowledgments

The author would like to thank the reviewers and the Guest Editor for helpful comments and suggestions, which led to an improved version of the manuscript.

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Copyright information

© Springer Science+Business Media New York (outside the USA) 2013

Authors and Affiliations

  1. 1.Office of Biostatistics ResearchNational Heart, Lung, and Blood InstituteBethesdaUSA

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