Outpatient Joint Arthroplasty-Patient Selection: Update on the Outpatient Arthroplasty Risk Assessment Score.

BACKGROUND: The Outpatient Arthroplasty Risk Assessment (OARA) score was designed to identify patients medically appropriate for same- and next-day discharge after surgery. The purpose of this study was to update and confirm the greater predictive utility of the OARA score in relation to American Society of Anesthesiologists Physical Status (ASA-PS) classification for same-day discharge and to identify the optimal preoperative OARA score for safe patient selection for outpatient surgery. METHODS: The perioperative medical records of 2051 primary total joint arthroplasties performed by a single surgeon at an academic tertiary care hospital were retrospectively reviewed. Six statistical measures were calculated to examine OARA score performance in binary classification of successful same-day discharge and preoperative OARA scores equal to 0 to 59 points (yes vs no) vs 0 to 79 points (yes vs no). RESULTS: Mean OARA scores increased more sharply in magnitude with increasing length of stay, providing superior discrimination than the ASA-PS classification with respect to same-day discharge. Preoperative OARA scores up to 79 points approached the desired 100% for positive predictive value (98.8%) and specificity (99.3%) and 0% for false positive rates (0.7%). CONCLUSION: The OARA score was designed to err in the direction of medical safety, and OARA scores between 0 and 79 are conservatively highly effective for identifying patients who can safely elect to undergo outpatient total joint arthroplasty. The ASA-PS classification does not provide sufficient discrimination for safely selecting patients for outpatient arthroplasty.

Safe Selection of Outpatient Joint Arthroplasty Patients With Medical Risk Stratification: the "Outpatient Arthroplasty Risk Assessment Score".

BACKGROUND: Current patient selection criteria and medical risk stratification methods for outpatient primary total joint arthroplasty (TJA) surgery are unproven. This study assessed the predictive ability of a medically based risk assessment score in selecting patients for outpatient and short stay surgery. METHODS: A retrospective review of 1120 consecutive primary TJAs in an early discharge program was performed. An Outpatient Arthroplasty Risk Assessment ("OARA") score was developed by a high-volume arthroplasty surgeon and perioperative internal medicine specialist to stratify patients as "low-moderate risk (≤59)" and "not appropriate" (≥60) for early discharge. OARA, American Society of Anesthesiologists Physical Status Classification System (ASA-PS), and Charlson comorbidity index (CCI) scores were analyzed with respect to length of stay. RESULTS: The positive predictive value of the OARA score was 81.6% for the same or the next day discharge, compared with that of 56.4% for ASA-PS (P < .001) and 70.3% for CCI (P = .002) scores. Patients with OARA scores ≤59 were 2.0 (95% confidence interval [CI], 1.4-2.8) times more likely to be discharged early than those with scores ≥60 (P < .001), while a low ASA-PS score was 1.7 (95% CI, 1.2-2.3) times more likely to be discharged early (P = .001). CCI did not predict early discharge (P ≥ .301). With deliberate patient education and expectations for outpatient discharge, the odds of early discharge predicted by the OARA score, but not the ASA-PS score, increased to 2.7 (95% CI, 1.7-4.2). CONCLUSION: The OARA score for primary TJA has more precise predictive ability than the ASA-PS and CCI scores for the same or next day discharge and is enhanced with a robust patient education program to establish appropriate expectations for early discharge. Early results suggest that the OARA score can successfully facilitate appropriate patient selection for outpatient TJA, although consideration of clinical program maturity before adoption of the score is advised.