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

backgroundNational 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.

methodsThe 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.

conclusionDetermining 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.