The women's health initiative: lessons learned

Annu Rev Public Health. 2008;29:131-50. doi: 10.1146/annurev.publhealth.29.020907.090947.


The Women's Health Initiative (WHI) was initiated in 1992 as a major disease-prevention research program among postmenopausal women. The program includes a randomized controlled intervention trial involving 68,132 women and four distinct interventions: conjugated equine estrogens, alone or in combination with medroxyprogesterone acetate, for coronary heart disease prevention with breast cancer as an anticipated adverse effect; a low-fat eating pattern for breast and colorectal cancer prevention; and calcium and vitamin D supplementation for hip fracture prevention. Results from this multifaceted trial have made a substantial impact in clinical practice. A companion cohort study among 93,676 women serves as a source for new risk factor information and provides a comparative observational assessment of the clinical trial interventions. A specimen repository and quality-controlled outcome data for a range of diseases are among the resources that support the ongoing research program. WHI clinical trial contributions and challenges are reviewed and discussed.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Aged
  • Breast Neoplasms / prevention & control*
  • Calcium, Dietary / administration & dosage
  • Colorectal Neoplasms / prevention & control*
  • Coronary Disease / prevention & control*
  • Diet, Fat-Restricted
  • Estrogen Replacement Therapy* / adverse effects
  • Female
  • Hip Fractures / prevention & control*
  • Humans
  • Middle Aged
  • Postmenopause*
  • Primary Prevention / methods
  • Randomized Controlled Trials as Topic
  • United States
  • Vitamin D / administration & dosage
  • Women's Health*


  • Calcium, Dietary
  • Vitamin D