Cost Difference in Performing Total Knee Arthroplasty at Ambulatory Surgical Centers Compared With Hospital-Based Outpatient Departments: Observational Study.

ABSTRACT

BACKGROUND: As total knee arthroplasty (TKA) further transitions toward an outpatient procedure, it becomes important to identify the resource utilization after TKAs at different outpatient facilities. The objective of this study was to determine the 90-day cost of patients who underwent TKAs at an ambulatory surgical center (ASC) or a hospital outpatient department (HOPD). METHODS: An observational cohort study was conducted using the Marketscan database with patients who had a TKA at an ASC or HOPD between January 1st, 2019, and October 2nd, 2021. The primary outcome was cost in a 90-day period (including the day of surgery), with inpatient admissions and ED visits as secondary outcomes. Multivariable regression analyses were conducted, adjusting for patient characteristics. RESULTS: The study population consisted of 47,261 patients with 7,874 ASC patients and 39,387 HOPD patients. 90-day costs for ASC patients were lower compared with HOPD patients ($35,634 ± 19,030 vs. $38,096 ± 24,389, P < 0.001). 90-day inpatient admission rates were lower for ASC than HOPD patients (2.5% vs. 4.8%, P < 0.001). 90-day ED visits for ASC patients were lesser compared with HOPD patients (8.9% vs. 12.7%, P < 0.001). CONCLUSION: Patients with TKAs at an ASC had an overall lower cost, inpatient admissions, and ED visits over a 90-day period compared with HOPD patients. Future consideration for which outpatient facilities patients have their TKA at is necessary as TKAs shift toward bundle payments and outpatient procedures.