Association between preoperative waiting time and hospital stay in older adults with hip fractures: A two-center retrospective study in Japan

Background: Hip fractures in older adults require surgery and frequently result in prolonged hospital stays. Recently, the revision of Japan's medical reimbursement system introduced an acute care incentive to promote early surgery for hip fracture cases, highlighting the need for timely intervention and efficient inpatient management. In this context, the present study aimed to identify factors associated with prolonged hospital stay in older adults undergoing hip fracture surgery at two acute care hospitals in Japan. Methods: A retrospective review was conducted on data from 1184 patients aged ≥65 years who underwent hip fracture surgery between April 2021 and March 2024. Patients were categorized into three groups based on their length of stay: ≤14 days (short group), 15–28 days (moderate group), and ≥29 days (long group). Multinomial logistic regression analysis was utilized to identify factors associated with prolonged hospital stays. Receiver operating characteristic curve analysis was conducted to determine the optimal cutoff for preoperative waiting time in predicting a prolonged hospital stay. Results: The short group included 260 patients (22.0%), the moderate group 631 (53.3%), and the long group 293 (24.7%). Multivariable analysis revealed that extended preoperative waiting time and living with others were independently associated with prolonged hospital stay. The odds ratio for being in the long group was 3.62 (95% confidence interval: 2.40–5.46) for a preoperative waiting time of ≥3 days compared with ≤2 days. The optimal cutoff for preoperative waiting time to predict a hospital stay ≥29 days was 2.5 days (area under the curve: 0.68; sensitivity: 62.8%; specificity: 62.5%), highlighting a clear window for surgical intervention. Conclusion: The preoperative waiting time was crucial factor influencing the length of hospital stay after hip fracture surgery in older adults. Timely surgical intervention within 2 days of admission can enhance care efficiency and shorten the hospitalization period.