Statistics in Biosciences

, Volume 5, Issue 2, pp 330–343 | Cite as

A Statistical Perspective on Prevention Trials: A View from the Women’s Health Initiative

  • Garnet L. AndersonEmail author
Case Studies and Practice Articles


Chronic disease prevention trials test strategies to reduce the risk of a specific health event in generally healthy people. These strategies are often thought to affect other health conditions and their use in the population requires a very favorable safety profile. A prevention trial assessing such a strategy is most valuable when designed to capture the overall public health impact and hence provide more comprehensive, reliable information for policy and practice. This broad agenda, and particularly the assessment of multiple outcomes, creates statistical challenges in the design, monitoring, and reporting of such a trial. In this article these issues are described in the context of the Women’s Health Initiative, a large randomized prevention trial testing three interventions in post-menopausal women: hormone therapy, a low-fat diet and calcium and vitamin D supplementation. Each intervention was hypothesized to influence multiple chronic disease rates including cardiovascular disease, stroke, cancers, and fractures. Here the design, monitoring, and reporting of the WHI trials is reviewed in the context of multiple outcomes and the approach to a global assessment of these interventions is described.


Multiple outcomes Trial monitoring Partial factorial design Post-menopausal hormone therapy Nutrition 



This work was supported by funding from the National Heart Lung Blood Institute: HHSN268201100046C. I would like to thank Susan Terjeson for assistance with this manuscript.


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Copyright information

© International Chinese Statistical Association 2013

Authors and Affiliations

  1. 1.Women’s Health Initiative Clinical Coordinating CenterFred Hutchinson Cancer Research CenterSeattleUSA

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