Abstract
BACKGROUND: Postoperative hyperactive delirium is a common and serious complication in older patients undergoing surgery, but the association between delirium and mortality remains controversial. Compared to other delirium subtypes, hyperactive delirium is characterized by more overt clinical manifestations, facilitating accurate detection and evaluation. This study aimed to clarify this association by comparing long-term mortality between patients with and without postoperative hyperactive delirium, using propensity score matching for robust analysis. METHODS: We conducted a cohort study to evaluate the association between postoperative hyperactive delirium and long-term mortality in older patients undergoing emergency hip fracture surgery. We used the Taiwan National Health Insurance Service database to identify patients aged 65 years or older who underwent emergency hip fracture surgery between 2008 and 2018. The primary outcome was all-cause mortality. RESULTS: A total of 270,437 patients were included in the analysis, with 6,795 patients in the postoperative hyperactive delirium group and 263,642 patients in the no postoperative hyperactive delirium group. After PSM, both groups contained 6,795 patients, ensuring balanced baseline characteristics for comparison. Postoperative hyperactive delirium was an independent risk factor for all-cause death, with an adjusted hazard ratio of 1.62 (95% confidence interval, 1.51-1.74; P < 0.0001) after PSM. Subgroup analysis revealed that older patients with postoperative hyperactive delirium consistently exhibited significantly higher adjusted hazard ratios of all-cause death compared with those without postoperative hyperactive delirium, regardless of age, sex, income levels, or ASA scores. Although the difference in 5-year overall survival between groups (81.7% vs. 89.8%, P < 0.0001) was statistically significant, the high survival rates in both groups suggest a modest absolute clinical impact. CONCLUSION: Postoperative hyperactive delirium is an independent risk factor for long-term mortality in older patients undergoing emergency hip fracture surgery. While the statistical association is evident, it is important to carefully consider the modest absolute difference in survival rates and its implications for clinical application.