Association Between Admission Glucose-to-Potassium Ratio and 30-Day Mortality in Elderly Patients With Hip Fractures

Objective: Hip fractures in the elderly represent a major public health concern, associated with significant short-term mortality and functional decline.Early risk stratification upon admission is essential to guide clinical management.The stress index (SI), defined as the glucose-to-potassium ratio, has emerged as a potential prognostic biomarker in various acute medical conditions.However, its role in predicting mortality in patients with traumatic hip fractures remains underexplored.Methods: This retrospective study included patients aged 18 years who presented to the emergency department of a teratiary care hospital with traumatic hip fractures between January 1, 2022, and January 1, 2024.Data were obtained from electronic health records, including demographic information, laboratory values at admission, vital signs, comorbidities, and 30-day mortality outcomes.The SI was calculated as the glucose-to-potassium ratio.The primary outcome was 30-day all-cause mortality.Predictive performance was assessed using receiver operating characteristic (ROC) analysis, and model calibration was evaluated using the Hosmer-Lemeshow test and Brier score.Results: A total of 440 patients were included, with a 30-day mortality rate of 9.3% (n=41).The stress index was significantly higher among non-survivors (40.5 [IQR 33.6-47.5])compared to survivors (32.4 [IQR 27.2-37.2],p<0.001).ROC analysis yielded an area under the curve of 0.794 (95% CI 0.726-0.860).The optimal cutoff value (Youden index) was 35.9, with 73.2% sensitivity and 76.4% specificity.Calibration metrics indicated good model fit and prediction accuracy. Conclusion:The admission SI is independently associated with 30-day mortality in elderly patients with traumatic hip fractures.As a rapid and accessible marker, it may enhance early risk stratification and inform clinical decision-making in emergency care settings.