Validation of the Outpatient Arthroplasty Risk Assessment tool for safe same-day discharge after primary shoulder arthroplasty: a retrospective expansion study

Abstract

BackgroundEarly discharge has been a target of cost-control efforts given the growing demand for joint replacement surgeries. A multisystem medically-based risk-assessment tool known as the Outpatient Arthroplasty Risk Assessment (OARA) score has shown high predictive ability for safe early discharge following an outpatient lower extremity arthroplasty utilizing a score threshold ≤79. Shoulder arthroplasties have been shown to have lower associated medical risks than lower extremity arthroplasties. An OARA score threshold of 110 was recently shown to be safe for same-day discharge (SDD) following shoulder arthroplasties in a series of 422 patients. The purpose of this study is to re-examine the OARA score threshold for shoulder arthroplasties by evaluating its effectiveness in selecting patients for SDD utilizing a larger population of patients. We hypothesize that the OARA score threshold for shoulder arthroplasty will remain higher than the established threshold for lower-extremity arthroplasty. MethodsA retrospective review was performed on 734 consecutive patients who underwent a primary anatomic or reverse total shoulder arthroplasty between April 2018 and December 2020 by a single surgeon. As standard practice, all patients were counseled preoperatively regarding SDD and given the choice to stay overnight. Medical history, length of stay, 30- and 90-day readmissions, and 90-day emergency room and urgent care visits were obtained from medical records. Analysis of variance testing, Chi-square testing, and screening test characteristics compared the performance of OARA scores to that of the American Society of Anesthesiologists Physical Status. A receiver operating characteristic analysis was completed to determine the optimal OARA score threshold for safe SDD. ResultsThe receiver operating characteristic analysis showed that 102.5 was the optimal preoperative OARA score threshold for safe SDD following a shoulder arthroplasty. The OARA score cutoff of ≤102.5 points demonstrated a sensitivity of 87.0% for identifying SDD patients. OARA scores ≤102.5 also showed a negative predictive value of 80.6% but remained incomprehensive with a specificity of 28.5% (P < .0001) and a positive predictive value of 39.2. Patients with OARA scores ≤102.5 were over 4 times less likely to have a 90-day emergency room visit (P < .001) than those with scores >102.5. There was no difference in 30-day and 90-day readmission rates for patients with OARA scores ≤102.5, ≤110, and ≤79 and American Society of Anesthesiologists Physical Status ≤2. ConclusionA preoperative OARA score threshold of ≤102.5 is effective and conservative in screening patients for SDD following a shoulder arthroplasty, with low rates of 90-day emergency room visits and readmissions. This threshold is a useful screening tool to identify patients that are not good candidates for SDD.