Background: Studies of volume-outcome relationships typically subdivide volume via non-evidence-based methods, producing categories that vary widely among studies, preclude the comparison of results, and possibly obscure the true volume-outcome relationships. The goal of the current study was to use quantitative methods to derive meaningful, riskbased categories for hospital and surgeon total hip arthroplasty (THA) volume based on relationships with mortality, complications, and revision. Methods: Using New York statewide patient data (1997 to 2014; n = 187,557), we derived risk-based hospital and surgeonvolume categories for primary THA based on relationships with 90-day complications and mortality and 2-year revision. Results: The following categories, based on relationships with complications, mortality, and revision, were derived for surgeon volume: 0 to 12, 13 to 25, 26 to 72, 73 to 165, 166 to 279, and ‡280 THA/year. For hospital volume, the categories derived were 0 to 11, 12 to 54, 55 to 157, 158 to 526, and ‡527 THA/year. More than 35% of THA cases in New York State were conducted by surgeons performing £1 THA/month (0 to 12 THA/year), and these were associated with a 2 to 2.5-fold increase in the risk for complications, mortality, and revision relative to higher-volume surgeons. Similarly, 15% of THA cases in New York State were conducted in hospitals performing £1 THA/week (0 to 11 or 12 to 54 THA/year), and these were associated with a nearly 1.5-fold increase in complications and between a 4 and 6-fold increase in mortality. Traditional non-evidence-based quartile categories were concentrated at lower volumes, did not capture the full magnitude of the volume-related differences, and were a poorer representation of the outcome data, as assessed by several model metrics. Thus, quartiles showed only a <2-fold increase in complications, mortality, and revision for the lowest versus the highest surgeon-volume quartile and failed to show the increased risk for lower versus higher hospital volumes. Conclusions: The volume-outcome relationships in THA are more pronounced than previously apparent through standard statistical techniques. Volume-based strategies for improving outcomes in THA should use benchmarks that are evidencebased to achieve optimal results. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
|Number of pages||6|
|Journal||Journal of Bone and Joint Surgery - American Volume|
|Publication status||Published - Jan 1 2018|
All Science Journal Classification (ASJC) codes
- Orthopedics and Sports Medicine