Examination of a Proposed 30-Day Readmission Risk Score on Discharge Location and Cost.

Abstract

BACKGROUND\nReadmissions cost an estimated $41 billion in the United States each year. To address this, a single institution recently developed a new risk model predictive of 30-day readmission following adult cardiac surgery. The purpose of this study is to validate and refine this new readmission risk model using a statewide database.\n\n\nMETHODS\nA total of 19,964 patients were analyzed using a statewide Society of Thoracic Surgeons database (2014-2017). The aforementioned multivariate model was replicated (Model 1): race, hospital length of stay, chronic lung disease, operation type, and renal failure. Model 2 also included discharge location. Thirty day readmission risk scores, low (0-10%), moderate (10-13%) and high (≥13%) risk categories were calculated.\n\n\nRESULTS\nThe overall 30-day readmission rate was 11.1% with both Models 1 and 2 predicting readmission (OR: 1.09; 95% CI: 1.08-1.11 vs. OR: 1.10; 95% CI: 1.08-1.11). Statistically significant differences were observed across all risk categories in discharge location and total cost. For Model 1 and 2, 86% of low risk patients were discharged to home vs. 66.9% and 42.9% of patients in high risk groups (p<0.001). The largest increases were observed with a Hospice discharge location for both Model 1($37,935 to $89,285) and Model 2 ($37,930 to $89,230).\n\n\nCONCLUSIONS\nBoth risk models significantly predicted 30-day readmission in our multi-institutional dataset confirming the score is valid and a generalizable quality improvement tool. The addition of discharge location and total cost adds valuable information of the ongoing efforts to identify patients at high risk for readmission.