Incidence of fractures compared to cardiovascular disease and breast cancer: The Women's Health Initiative Observational Study

Summary: To compare the absolute risk of fracture to the risk of other conditions by race/ethnicity, we studied 83,724 women, aged 70-79. The projected number of fractures was similar to or exceeded the combined number of cardiovascular events and breast cancers. Osteoporosis prevention efforts should target women of all ethnicities. Introduction: The relative risk of fracture is lower in non-white compared to white women but the absolute risk of fracture in comparison to other common chronic conditions is uncertain. Methods: We performed a prospective cohort study of 83,724 women, age 50-79 years. Cardiovascular disease (CVD), invasive breast cancer and all fractures were identified over an average of 7.7 ± 2.6 years. Results: The incidence of fracture, breast cancer, stroke and CVD varied across ethnicity. The annualized (%) incidence of fracture was greatest in whites (2.4%) and American Indians (2.8%) and lowest among blacks (1.3%). The majority of hip fractures occurred in white women. The projected number of women who will experience a fracture in one year exceeded the combined number of women who would experience invasive breast cancer or a broad category of CVD events in all ethnic groups except blacks. In 10,000 black women, an estimated 153 women would experience CVD, and 35 women, breast cancer compared to 126 women expected to fracture in one year. Conclusion: The annual risk of suffering a fracture is substantial in women of all ethnicities. Osteoporosis prevention efforts should target all women irrespective of their race/ethnic backgrounds.