The "Outpatient Arthroplasty Risk Assessment" Score for Same Day Outpatient Primary Total Joint Arthroplasty: A Multicenter Study.

Abstract

The Outpatient Arthroplasty Risk Assessment (OARA) Score was developed to risk-stratify patients for safe same-day discharge outpatient total joint arthroplasty (TJA). It has demonstrated predictive ability for length of stay in primary TJA. However, there is minimal external validity of the original studies. This multicenter database study evaluated the risk assessment and predictive ability for same-day discharge of the OARA score and clinical outcomes following primary TJA. From 2017 to 2023, across 40 locations, 12,809 primary TJAs (4,656 hips and 8,153 knees) were identified. A total of 5,552 and 4,974 cases had length of stay, complication, and readmission data, respectively. Overall, 1,864 (34%) patients were discharged on the same day after primary TJA. Machine learning and statistical models evaluated the predictive ability of the OARA score on same-day discharge, readmission rates, and complications within 90 days. P-values ≤ 0.05 were considered statistically significant. Patients who had an OARA score < 60 and < 80 were ≥ 2.6 times more likely to be discharged on the same day of surgery. A lower OARA score was associated with proportionally fewer complications and readmissions (P ≤ 0.001). Complications and readmissions were 2.9 to 3.1 and 3.1 to 3.3 times more likely with OARA scores ≥ 60 and ≥ 80, respectively. Study results demonstrate that patients who had lower OARA scores are more likely to be discharged the same day and have lower complication or readmission rates after primary TJA. These results from multiple centers across the United States further support the original studies and provide evidence for the continued use of the OARA score to help identify medically appropriate candidates for outpatient primary TJA. III.