Economic advantage of outpatient shoulder arthroplasty: a Markov model analysis.

Background: Outpatient total shoulder arthroplasty (TSA) has become increasingly common due to advances in perioperative care and policy changes. While prior studies have demonstrated lower short-term costs associated with outpatient TSA, its long-term economic value compared with inpatient TSA remains unclear. Methods: A Markov cost-utility model compared outpatient and inpatient TSA from a U.S. payer perspective over a 20-year horizon. Costs and quality-adjusted life-years (QALYs) were discounted at 3%. Cost-effectiveness was evaluated at a willingness-to-pay threshold of $100,000 per QALY, with probabilistic sensitivity analyses varying readmission and revision risks. Results: In the base case analysis, outpatient TSA was the dominant strategy. Mean discounted lifetime costs were lower for outpatient TSA compared with inpatient TSA ($23,375 vs. $28,402), resulting in a cost savings of $5,027 per patient. Outpatient TSA was associated with a modest increase in effectiveness, generating 10.436 QALYs compared with 10.427 QALYs for inpatient TSA (incremental gain, 0.009 QALYs). In probabilistic sensitivity analysis, outpatient TSA demonstrated a mean incremental cost of -$5,142 (95% uncertainty interval, -$13,642 to $3,109) and a mean incremental effectiveness of 0.009 QALYs (95% uncertainty interval, -0.034 to 0.057). At a willingness-to-pay threshold of $100,000 per QALY, outpatient TSA was cost-effective in 89.0% of simulations and economically dominant in 61.1% of simulations. Conclusions: Outpatient TSA is a cost-effective and economically dominant strategy compared with inpatient TSA, driven primarily by lower initial procedural costs. Sensitivity analyses demonstrated that outpatient TSA remained cost-effective even when differences in perioperative complication and revision rates were substantially reduced.