The Women's Health Initiative (WHI)

The Women's Health Initiative (WHI) was initiated by the U.S. National Institutes of Health (NIH) in 1991. The Women's Health Initiative consisted of clinical trials and observational research conducted to address major health issues causing morbidity and mortality in postmenopausal women. In particular, randomized controlled trials were designed and funded that addressed cardiovascular disease, cancer, and osteoporosis. In its entirety, the WHI studied more than 160,000 postmenopausal women aged 50-79 years over 15 years.