Death and Postoperative Complications After Hip Fracture Repair: Dialysis Effect

INTRODUCTION: It is unknown whether patients receiving dialysis have a higher morbidity and mortality risk after hip fracture repair conferred by their kidney failure or by the high comorbidity burden often present. METHODS: We examined associations of dialysis dependency with postoperative complications, death, and readmission in a matched cohort study of U.S. patients undergoing hip fracture repair, from January 2010 to December 2013, in the American College of Surgeons National Surgical Quality Improvement Program. Matching included sex, age, race, diabetes mellitus, operation year, primary surgery type, and anesthesia technique. RESULTS: Among 22,621 patients, 377 dialysis-dependent patients were matched to 1508 nondialysis patients. Median age was 78 years (interquartile range = 68−85) years, 56% were men, 70% were white, 43% had diabetes, and 47% underwent fracture fixation under mostly (80%) general anesthesia. Dialysis-dependent patients had higher physical status classification, had more heart failure and hypoalbuminemia, and were less often smokers. After adjustment, a greater risk of prolonged postoperative stays beyond 7 days (odds ratio [OR] = 1.43, 95% confidence interval [CI] = 1.09−1.89), higher in-hospital mortality (OR = 3.13, CI = 1.72−5.7), and 30-day death (OR = 2.29, CI = 1.51−3.48) but not 30-day readmission (P = 0.09) was observed with dialysis dependency. Adjusted analyses in the original cohort (n = 22,621) were similar: the dialysis group had greater risk of prolonged postoperative stay (OR = 1.77, CI = 1.42−2.21), in-hospital mortality (OR = 2.65, CI = 1.74−4.05), and 30-day death (OR = 2.03, CI = 1.48−2.80) and 30-day readmission (OR = 1.62, CI = 1.66−2.26). CONCLUSION: Dialysis dependency is associated with an increased risk of death and postoperative complications after hip fracture repair. These findings have implications for case-mix adjustment and quality metrics.