Chronic Disease Prevention Trials: Challenges, Lessons, and Opportunities in the Women's Health Initiative

• Activity Number: 462
• Type: Invited
• Date/Time: Wednesday, August 7, 2013 : 8:30 AM to 10:20 AM
• Sponsor: International Chinese Statistical Association
• Author(s): Garnet L. Anderson*+
• Companies: Fred Hutchinson Cancer Research Center
• Keywords: embedded trials ; multiple outcomes ; chronic disease prevention ; public health ; cohort studies

Abstract

Chronic disease prevention trials provide opportunities for statistical contributions of direct importance to public health. The Women's Health Initiative (WHI) provides a particularly useful motivating example. The WHI tested the effects of three prevention interventions (hormone therapy, a low-fat diet, and calcium/vitamin D supplements) on overall health in postmenopausal women. A large observational study was conducted in parallel. Statistical challenges in trial design, monitoring and reporting arose from the need for a robust assessment of risks and benefits across multiple clinical outcomes. Large discrepancies between trial findings and prior studies of hormone therapy stimulated novel joint analyses of the observational study and the clinical trial which yielded important additional insights. These analyses suggest approaches for embedding trials in observational studies to increase generalizability, expand inference, and increase power. Such designs may be particularly useful for prevention trials where it is increasingly important to leverage existing research resources such as large cohort studies.