Early Postoperative Prognostic Nutritional Index, Dementia, and Walking Independence at Discharge in Patients with Hip Fracture: A Multicenter Observational Study.

Objectives: This study investigated whether early postoperative Prognostic Nutritional Index (PNI), dementia, and physical function are associated with walking independence at discharge in patients with hip fracture. Methods: This multicenter retrospective observational study included 173 complete-case patients aged 65 years or older who had been independent ambulators before hip fracture surgery. The primary outcome was walking independence at discharge. Early postoperative PNI was calculated from serum albumin concentration and total lymphocyte count at 1 week postoperatively. Physical function was assessed using single-leg standing time and weight-bearing ratio on the non-affected side. Multivariable logistic regression, receiver operating characteristic (ROC) analysis, and sensitivity analyses were performed. Results: Among 173 patients, 85 were independent walkers and 88 were non-independent walkers at discharge. Multivariable logistic regression analysis showed that lower PNI at 1 week postoperatively [odds ratio (OR) per 1-point increase, 0.86; 95% confidence interval (CI), 0.80-0.92; P <0.001] and dementia (OR, 6.32; 95% CI, 2.75-15.87; P <0.001) were independently associated with non-independent walking at discharge. These associations remained consistent in sensitivity analyses including adjustment for log-transformed C-reactive protein and a parsimonious model including age, dementia, and PNI. The area under the ROC curve for PNI was 0.66 (95% CI, 0.58-0.74). Conclusions: Early postoperative PNI and dementia were independently associated with non-independent walking at discharge. PNI may serve as an adjunctive marker for early risk stratification in patients with hip fracture.