Appendicular bone mineral and a woman's lifetime risk of hip fracture

Appendicular bone mass is inversely related to the risk of hip fracture in short‐term prospective studies, but hip fractures typically occur about 30 years after menopause. We developed a model that estimates a woman's lifetime risk of hip fracture based on measurement of radial bone mass at age 50 using short‐term prospective data relating bone mass to hip fracture, the correlation between bone mass at age 50 and later years, the age‐specific incidence of hip fracture and mortality, and prospective data about bone mass and mortality. We estimate that a 50‐year‐old white woman has a 19% lifetime risk of hip fracture if her radial bone mass is at the 10th percentile for her age and an 11% lifetime risk if her bone mass is at the 90th percentile. Improved measurement techniques that have a higher predictive value for hip fracture in short‐term studies could substantially increase this gradient of lifetime risk and therefore be more clinically useful.