Incidence, Cost, and Risk Factors for Readmission After Coronary Artery Bypass Grafting

Abstract

Background: Readmissions adversely affect hospital reimbursement and quality measures. We aimed to evaluate the incidence, cost, and risk factors for readmission following coronary artery bypass grafting (CABG).

Methods: We queried the National Readmissions Database and isolated patients who underwent CABG from 2013 to 2014. We determined the top reasons for readmission and compared demographics, comorbidities, in-hospital outcomes, and costs between readmitted and nonreadmitted patients. Generalized linear regression was performed to identify independent predictors for readmission.

Results: We identified 288,059 patients who underwent isolated CABG in the United States between 2013 and 2014. A total of 12.2% were readmitted within 30 days of discharge. Postoperative infection, heart failure, and arrhythmia were the most common reasons for readmission. The median time to readmit was 11 days, with a length of stay (LOS) of 6 days and a cost of $13,499 ± $201. Independent preoperative predictors for readmission were Medicaid status (odds ratio [OR], 1.33), female sex (OR, 1.32), chronic renal failure (OR, 1.26), greater than 4 Elixhauser comorbidities (OR, 1.20), chronic pulmonary disease (OR, 1.15), and nonelective operation (OR, 1.10) (all p < 0.05). In-hospital predictors included LOS greater than 10 days (OR, 1.52), acute kidney injury (OR, 1.30), atrial fibrillation (OR, 1.20), pneumonia (OR, 1.13), and discharge to skilled nursing facility (OR, 1.43) (all p < 0.05).

Conclusions: Thirty-day readmissions after CABG are frequent and related to preoperative comorbidities and complex postoperative course. Medicaid status, prolonged LOS, and disposition to a skilled nursing facility are strong predictors for 30-day readmission following CABG. Readmission reduction efforts should consider improvements for patients in these cohorts.