Hospital Frailty Risk Score predicts adverse events in older patients with hip fractures after surgery: Analysis of a nationwide inpatient database in Japan

Background: Frailty may predict adverse events in patients with hip fractures. This study aimed to investigate the association between frailty and adverse events in patients with hip fractures after surgery using information from Japanese health insurance. Methods: This retrospective cohort study included patients with hip fractures aged >= 65 years using a nationwide database in Japan. We examined the relationship of the frailty risk, which was defined using the Hospital Frailty Risk Score (HFRS), with in-hospital mortality, complications such as delirium and pneumonia, and functional outcomes. We used descriptive analysis, logistic regression, and linear regression analysis to estimate the association between the HFRS and outcomes in patients with hip fracture. Results: We analysed data from 36,192 patients with hip fractures after surgery (mean age: 83.6 +/- 6.7 years, female: 79.5%). The proportions of low, intermediate, and high risk of frailty were 68.4%, 28.1%, and 3.5%, respectively. The frailty risk was independently associated with in-hospital mortality (intermediate risk: odds ratio [OR] 1.385, P < 0.001; high risk: OR 1.572; P < 0.001) and the occurrence of complications. Furthermore, each frailty risk was negatively associated with the Barthel Index score at discharge (intermediate risk: coefficient -11.919, P < 0.001; high risk: coefficient -18.044; P < 0.001). Conclusions: The HFRS could predict adverse events, including in-hospital mortality, in Japanese older patients with hip fractures. This finding supports the validity of using the HFRS in clinical practice for patients with hip fractures.