Is Outpatient Arthroplasty as Safe as Fast-Track Inpatient Arthroplasty? A Propensity Score Matched Analysis

Abstract

Background: In the emerging fiscal climate of value-based decision-making and shared risk and remuneration, outpatient total joint arthroplasty is attractive provided the incidence of costly complications is comparable to contemporary "fast-track" inpatient pathways.

Methods: All patients undergoing total hip arthroplasty or total knee arthroplasty between 2011 and 2013 were selected from the American College of Surgeons-National Surgical Quality Improvement Program database. A propensity score was used to match 1476 fast-track (≤2 day length of stay) inpatients with 492 outpatients (3:1 ratio). Thirty-day complication, reoperation, and readmission rates were compared, both during and after hospitalization. Logistic regression was used to calculate propensity score adjusted odds ratios.

Results: After matching, outpatients had higher rates of medical complication (anytime, 10.0% vs 6.7%, P = .018; post discharge, 6.3% vs 1.1%, P < .001). Most complications were bleeding requiring transfusion, which occurred at similar rates after surgery but at higher rates post discharge in outpatients (anytime, 7.5% outpatients vs 5.6% inpatients, P = .113; post discharge, 4.1% outpatients vs 0.1% inpatients, P < .001). There was no difference in readmission rate (2.4% outpatient vs 2.0% inpatient, P = .589).

Conclusion: Outpatients experience higher rates of post-discharge complications, which may countermand cost savings. Surgeons wishing to implement outpatient total joint arthroplasty clinical pathways must focus on preventing post-discharge medical complications to include blood management strategies.

Keywords: complications; outcomes; outpatient hip arthroplasty; outpatient knee arthroplasty; readmissions.