Women's Health Initiative Strong and Healthy (WHISH): A pragmatic physical activity intervention trial for cardiovascular disease prevention.

BACKGROUND: National guidelines promote physical activity to reduce cardiovascular disease (CVD); yet, no RCT has tested the effectiveness of physical activity as the sole intervention for primary CVD prevention in older adults. The Women's Health Initiative (WHI) Strong and Healthy (WHISH) trial, a pragmatic trial embedded in the WHI-Extension Study (ES), is testing whether increasing physical activity and decreasing sedentary behavior will reduce major CV events in older women.
METHODS: The randomized consent design was used to assign 49,331 women (aged 68-99 years in 2015) who had consented to ongoing WHI-ES follow-up and for whom CV outcomes were available through WHI-ES procedures (N = 18,985) and/or linkage to the Centers for Medicare and Medicaid Services (N = 30,346) to a physical activity (PA) intervention designed to promote national recommendations (N = 24,657) or "usual activity" comparison (N = 24,674). Women assigned to the intervention provided passive consent to receive the intervention and provide data. A multi-component PA intervention is delivered by seasonal (quarterly) newsletters with targeted inserts (lower, middle, higher) based on self-reported levels of physical functioning (PF) and physical activity; monthly motivational telephone messages; monthly emails; a website; and contact with staff, as requested. Major CV events, myocardial infarction (MI), stroke, or CVD death, collected annually through WHI-ES, comprise the primary outcome. Hip fracture and non-CVD death are primary safety outcomes. Intention-to-treat analyses in all randomized participants will include 8 years of follow-up.
CONCLUSION: Determining whether increased physical activity and decreased sedentary behavior reduce major CV events in older women is of major public health significance. CLINICAL TRIALS REGISTRATION: ClinicalTrials.govidentifier:NCT02425345.