Survival after hip fracture

Abstract

Although it is known that overall mortality is increased after hip fracture, the influence of hip fracture risk factors on the subsequent mortality and cause of death has not been well studied. The objective of this study was to establish the survival after hip fracture in women and to assess the impact of comorbidity on mortality. We identified a complete population-based set of 2,245 incident hip fracture cases and 4,035 randomly selected population-based controls among women 50-81 years old in Sweden and followed these subjects for an average of 5 years through the Swedish National Inpatient and Cause-of-Death Registers. Information on factors related to hip fracture was obtained through linkage to hospital discharge data and through a mailed questionnaire. We studied excess mortality of hip fracture patients compared to controls using survival curves and proportional hazard regression models. During follow-up, 896 hip fracture patients (40%) and 516 (13%) controls died. The relative risk (RR) of death, adjusted for age and previous hospitalization for serious disease, was 2.3 (95% CI 2.0-2.5). Although the highest mortality risks were in the 1st 6 months post-fracture, RRs for fractures versus controls were increased for at least 6 years. Increased mortality was apparent both in those with evidence of comorbidity and those without. Hip fracture patients have a substantially increased risk of death that persists for at least 6 years post-fracture. The relative excess mortality is independent of comorbidity and known hip fracture risk factors.