Effect of Hospital and Surgeon Volume on Hospital Costs for Total Knee Arthroplasty

Abstract Purpose: Higher hospital or surgeon volume is shown to be associated with better patient outcomes following primary total knee arthroplasty (TKA). However, little research exists on the relationship between hospital and surgeon volume and inpatient costs of TKA. To explore the volume-cost relationship for primary TKA and to determine whether both hospital volume and surgeon volume are independently associated with lower inpatient costs. Methods: Statewide Planning and Research Cooperative System (SPARCS) claims data from the New York State Department of Health were used to identify 102,386 adults who underwent primary TKA from 2013 to 2016. Surgeon volume was defined as the number of TKA cases a surgeon had operated during the previous 365 days of the current case. Hospital volume was defined in a similar way. Hospital and surgeon volumes were categorized as tertile groups. Generalized linear models adjusted for patient, hospital, surgeon, and market covariates.Main Outcome Measures: Inpatient cost calculated as total charges multiplied by cost-to-charge ratios (CCR) and adjusted for inflation.Results: Compared with patients operated by low-volume surgeons in low-volume hospitals, patients of high-volume surgeons in high-volume hospitals had significantly lower inpatient costs (adjusted cost savings = $3,384 per TKA case, 95% confidence interval $3,184 - $3,583, P < 0.001). The inverse volume-cost relationship tended to be stronger in more recent years.Conclusions: TKAs performed at hospitals and by surgeons with higher volumes had significantly lower inpatient costs, especially in more recent years. Regionalization of TKA to high-volume hospitals and surgeons may achieve both better patient outcomes and cost savings.