Excess mortality following hip fracture: The role of underlying health status

Summary: We evaluated the long-term excess mortality associated with hip fracture, using prospectively collected data on pre-fracture health and function from a nationally representative sample of U.S. elders. Although mortality was elevated for the first six months following hip fracture, we found no evidence of long-term excess mortality. Introduction: The long-term excess mortality associated with hip fracture remains controversial. Methods: To assess the association between hip fracture and mortality, we used prospectively collected data on pre-fracture health and function from a representative sample of U.S. elders in the Medicare Current Beneficiary Survey (MCBS) to perform survival analyses with time-varying covariates. Results: Among 25,178 MCBS participants followed for a median duration of 3.8 years, 730 sustained a hip fracture during follow-up. Both early (within 6 months) and subsequent mortality showed significant elevations in models adjusted only for age, sex and race. With additional adjustment for pre-fracture health status, functional impairments, comorbid conditions and socioeconomic status, however, increased mortality was limited to the first six months after fracture (hazard ratio [HR]: 6.28, 95% CI: 4.82, 8.19). No increased mortality was evident during subsequent follow-up (HR: 1.04, 95% CI: 0.88, 1.23). Hip-fracture-attributable population mortality ranged from 0.5% at age 65 among men to 6% at age 85 among women. Conclusions: Hip fracture was associated with substantially increased mortality, but much of the short-term risk and all of the long-term risk was explained by the greater frailty of those experiencing hip fracture.