Trends in outpatient versus inpatient total shoulder arthroplasty over time

BACKGROUND: The purpose of this study was to investigate the safety of outpatient and inpatient total shoulder arthroplasty (TSA) and to investigate changes over time. METHODS: Patients undergoing primary TSA during 2006-2019 as part of the American College of Surgeons National Surgical Quality Improvement Program were identified. Patients were divided into an early cohort (2006-2016, 12,401 patients) and a late cohort (2017-2019, 12,845 patients). Outpatient procedures were defined as those discharged on the day of surgery. Patient comorbidities and rate of adverse events within 30 days postoperatively were compared with adjustment for baseline characteristics using standard multivariate regression. RESULTS: There was a significant reduction in complications over time when considering all cases (5.69% in the early cohort vs. 3.67% in the late cohort, adjusted relative risk [RR] = 0.65, 95% confidence interval [CI] = 0.58-0.73, P < .001). The rate of complications decreased over time among inpatients (5.80% vs. 3.90%, adjusted RR = 0.68, 95% CI = 0.60-0.76, P < .001). However, there was no difference in the rate of complications among outpatients over time (1.98% vs. 1.38%, adjusted RR = 0.64, 95% CI = 0.28-1.47, P = .293). There were significantly more complications among inpatients vs. outpatients in both the early and late cohorts (early: 5.80% vs. 1.98%, adjusted RR = 2.57, 95% CI = 1.24-5.34, P = .011, late: 3.90% vs. 1.38%, adjusted RR = 2.28, 95% CI = 1.39-3.74, P = .001). TSA became more common in elderly patients over 70 years of age over time in both the inpatient and outpatient cohorts, whereas fewer young patients (aged 18-59 years) underwent TSA in the late cohorts than in the early cohorts for both the inpatient and outpatient samples (P < .001). CONCLUSION: The overall complication rate of TSA has decreased over time as outpatient TSA has become increasingly common. When contemporary data are examined, the complication rate of outpatient procedures has remained constant over time while that of inpatient procedures decreased, despite the changing demographics of patients undergoing TSA. This indicates that outpatient TSA remains a safe procedure as patient selection criteria have evolved, while the safety of inpatient TSA continues to improve.