Development of a Risk Score to Predict 90-day Readmission after Coronary Artery Bypass Graft

Abstract 250/250 Background Readmission after coronary artery bypass grafting (CABG) is used for quality metrics and may negatively impact hospital reimbursement. Our objective was to develop a risk score system from a national cohort that can predict 90-day readmission risk for CABG patients. Methods Using the National Readmission Database between 2013-2014, we identified 104,930 patients discharged after CABG which account for 234,483 patients after weighted analysis. Using structured random sampling, patients were divided into a training (60%) and test data set (40%). In the training data set, we utilized multivariable analysis to identify risk factors. A point system risk-score was developed based on the odds ratios (OR). Variables with OR Results In the United States, the overall 90-day readmission rate after CABG was 19% (n=44,559/234,483). Nine demographic and clinical variables were identified as significant in the training data set. The final risk score ranged from 0-52, with the two largest risks associated with length of stay >10 days (score=+10) and Medicaid insurance (score=+7). The final model’s c-statistic was 0.67. Using an optimal cutoff point of 18 points, the accuracy of the risk score was 77%. Conclusions Ninety-day readmission after CABG surgery is frequent. A readmission risk-score higher than 18 points predicts readmission in 77% of patients. Based on 9 demographic and clinical factors, this risk score can be used to target high-risk patients for additional post-discharge resources to reduce readmission.