Risk Factors for Discharge to a Non-Home Destination and Reoperation Following Outpatient Total Hip Arthroplasty (THA) in Medicare-Eligible Patients

INTRODUCTION: The Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the inpatient-only (IO) list in January 2020. Given this recommendation, we analyzed Medicare-eligible patients undergoing outpatient THA to understand risk factors for nonroutine discharge, reoperations, and readmissions. MATERIALS AND METHODS: The 2015-2018 American College of Surgeons–National Surgical Quality Improvement Program database was queried using Current Procedural Terminology code 27130 for Medicare eligible patients (≥ 65 years of age) undergoing outpatient THA. Postoperative discharge destination was categorized into home and non-home. Multivariate logistic regression models were used to evaluate risk factors associated with non-home discharge disposition. Secondarily, we evaluated rates and risk factors associated with 30-day reoperations and readmissions. RESULTS: A total of 1095 THAs were retrieved for final analysis. A total of 108 patients (9.9%) experienced a non-home discharge postoperatively. Patients were discharged to rehab (n = 47; 4.3%), a skilled care facility (n = 47; 4.3%), a facility that was “home” (n = 8; 0.7%), a separate acute care facility (n = 5; 0.5%), or an unskilled facility (n = 1; 0.1%). Independent factors for a non-home discharge were American Society of Anesthesiologists Class >II (odds ratio [OR] 2.74), operative time >80 minutes (OR 2.42), age >70 years (OR 2.20), and female gender (OR 1.67). Eighteen patients (1.6%) required an unplanned reoperation within 30 days. A total of 40 patients (3.7%) required 30-day readmissions, with 35 readmissions related to the original THA procedure. Independent risk factors for 30-day reoperation were COPD (OR 5.85) and HTN (OR 5.24). Independent risk factors for 30-day readmission were HTN (OR 4.35) and Age >70 (OR 2.48). DISCUSSION: The current study identifies significant predictors associated with a non-home discharge, reoperation, and readmission in Medicare-aged patients undergoing outpatient THA. CONCLUSION: Providers should consider preoperatively risk-stratifying patients to reduce the costs associated with unplanned discharge destination, complication or reoperation.