Effect of Dementia on Outcomes After Surgically Treated Hip Fracture in Older Adults

Background: Hip fractures are associated with increased mortality and functional limitations. However, the effect that dementia has on these outcomes in individuals in aged care settings after fracture is not well established. This study examined the association of dementia with post-hip fracture mortality, permanent residential aged care entry, transition care use, and change in activities of daily living (ADL) needs. Methods: A retrospective cohort study using data from the Registry of Senior Australians (2003-2015) was conducted. Individuals with a hip fracture while receiving aged care services were included. Associations of dementia with mortality, risks of transition and permanent care use, and ADL needs progression were estimated using multivariable Cox, Fine-Gray, and logistic regression methods, respectively. Results: Of 4771 individuals evaluated, 76% were women, the median age was 86 years (IQR 82-90), and 71% already lived in permanent residential aged care at the time of fracture. Within two years of their hip fracture, 50.4% (95% CI 48.9%-51.8%) of individuals died, 16.2% (95% CI 14.2%-18.2%) entered a transition care program, 59.1% (95% CI 56.5%-61.7%) entered permanent residential aged care, and 32% had greater ADL needs. Dementia was associated with higher risk of two-year mortality (HR = 1.19, 95% CI 1.09-1.30), 90-day entry into permanent care (sHR = 1.96, 95% CI 1.60-2.38), and increased likelihood of ADL limitations (OR = 1.36, 95% CI 1.00-1.85). Minor differences were seen in transition care use by dementia status. Conclusion: Dementia is a strong risk factor for mortality after hip fractures in individuals in aged care settings and associated with a high risk of entry into permanent care. Level of Evidence: Prognostic level III.