Abstract

Purpose: The purpose of this study was to analyze the association between mortality and the prevalence of delirium in patients with hip fracture using national claim data.

Method: This cohort study was conducted from 2010 to 2013, including diagnostic criteria for hip fractures (femoral neck fractures or femur fractures) over 50 years of age. Operational definitions of delirium include disease code and drug use. The mortality rate was calculated using the Charlson's comorbidity index and statistically analyzed using the Cox proportional hazards regression analysis.

Results: A total of 1,587 patients, 209 patients (13.2%) had delirium during hospitalization (66 (31.6%) in males, 143 (68.4%) in females). After adjusting for the comorbidity index, the mortality rate in patients with postoperative delirium was 1.42 times higher than for the patients without delirium during over a mean 17-month follow-up (HR = 1.42, 95% CI; 1.07–1.87, p = 0.007). During the follow-up duration at four years, the cumulative mortality rates were higher in the delirium group (24.3% at one year, 31.8% at two years, 35.8% at three years, and 37.8% at four years, respectively) than in the non-delirium group (14.8% at one year, 21.7% at two years, 24.9% at three years, and 25.5% at four years, respectively).

Conclusion: In this nationwide study, the prevalence of delirium during the hospital stay after hip fracture surgery was 13.2% and the mortality rate in patients with postoperative delirium was 1.42 times higher than for the patients without delirium during a mean 17-month follow-up.