Osteoporosis and hip fractures.

Epidemiologic studies have contributed to our understanding of osteoporosis through identification of groups at high risk of fracture and through discernment of factors associated with increased risk of low bone density and fracture. Many of the questions remaining can be addressed only through the use of epidemiologic methods in human populations. These include longitudinal studies in large cohorts to better delineate factors associated with bone loss and fracture and randomized clinical trials to adequately assess therapies. Particularly needed are studies in adolescents to assess determinants of peak bone mass and the effect of subsequent bone loss with aging.