Age-specific loss of life expectancy after hip fracture in Asian adults: A nationwide population-based cohort study

Abstract

Background: Hip fracture is associated with excess mortality beyond the acute post-fracture period but is often regarded as a transient event after clinical recovery. The magnitude of residual life expectancy loss and its variation across age groups remain inconclusive. Methods: We conducted a nationwide cohort study using the National Health Insurance Service database of South Korea. Adults aged >= 50 years with incident hip fractures between 2010 and 2018 were identified and matched 1:2 by age and sex to individuals without fracture. To assess long-term mortality, follow-up began one year after the index date using a landmark approach. Mortality risk was evaluated using Cox proportional hazards models with sequential adjustment for age, comorbidities, and anti-osteoporotic medication use. Loss of life expectancy was estimated using restricted mean survival time analysis. The RMST time horizon (tau) was defined as the maximum common follow-up time across the compared groups within each age stratum, which corresponded to approximately 13.5 years in this dataset. Results: The study included 39,670 individuals with hip fracture and 73,428 matched controls from the South Korean population. Both men and women with hip fracture experienced persistently higher mortality than controls beyond the initial fracture event. Relative mortality risks were highest in younger adults and declined with advancing age. In contrast, the greatest absolute residual loss of life expectancy occurred among individuals aged 70-79 years, amounting to 2.94 years in men and 2.03 years in women. Residual life expectancy loss was more pronounced among individuals with diabetes mellitus and lower socioeconomic status. Conclusions: Hip fracture was associated with sustained reductions in life expectancy beyond the acute postfracture period in this nationwide cohort of South Koreans. Quantifying age-specific life expectancy loss clarifies long-term mortality risk after hip fracture and provides clinically interpretable estimates across age groups.