Risk factors and indications for readmission after lower extremity amputation in the American College of Surgeons National Surgical Quality Improvement Program

Background: Postoperative readmission, recently identified as a marker of hospital quality in the Affordable Care Act, is associated with increased morbidity, mortality, and health care costs, yet data on readmission after lower extremity amputation (LEA) are limited. We evaluated risk factors for readmission and postdischarge adverse events after LEA in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). Methods: All patients undergoing transmetatarsal (TMA), below-knee (BKA), or above-knee amputation (AKA) in the 2011-2012 NSQIP were identified. Independent predischarge predictors of 30-day readmission were determined by multivariable logistic regression. Readmission indication and reinterventions, available in the 2012 NSQIP only, were also evaluated. Results: We identified 5732 patients undergoing amputation (TMA, 12%; BKA, 51%; AKA, 37%). Readmission rate was 18%. Postdischarge mortality rate was 5% (TMA, 2%; BKA, 3%; AKA, 8%; P < .001). Overall complication rate was 43% (in-hospital, 32%; postdischarge, 11%). Reoperation was for wound-related complication or additional amputation in 79% of cases. Independent predictors of readmission included chronic nursing home residence (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.0-1.7), nonelective surgery (OR, 1.4; 95% CI, 1.1-1.7), prior revascularization/amputation (OR, 1.4; 95% CI, 1.1-1.7), preoperative congestive heart failure (OR, 1.7; 95% CI, 1.2-2.4), and preoperative dialysis (OR, 1.5; 95% CI, 1.2-1.9). Guillotine amputation (OR, 0.6; 95% CI, 0.4-0.9) and non-home discharge (OR, 0.7; 95% CI, 0.6-1.0) were protective of readmission. Wound-related complications accounted for 49% of readmissions. Conclusions: Postdischarge morbidity, mortality, and readmission are common after LEA. Closer follow-up of high-risk patients, optimization of medical comorbidities, and aggressive management of wound infection may play a role in decreasing readmission and postdischarge adverse events.