Abstract
BACKGROUND
High-volume surgeons and hospital systems have been shown to deliver higher value care in several studies. However, no evidence-based volume thresholds for cost currently exist in total hip arthroplasty (THA). The objective of this study was to establish clinically meaningful volume thresholds based on cost for surgeons and hospitals performing THA. A secondary objective was to analyze the relative market share of THAs among the newly defined surgeon and hospital volume strata.
METHODS
Using 136,501 patients from the New York State Department of Health's SPARCS database undergoing total hip arthroplasty, we used stratum-specific likelihood ratio (SSLR) analysis of a receiver operating characteristic (ROC) curve to generate volume thresholds predictive of increased costs for both surgeons and hospitals. Additionally, we examined the relative proportion of annual THA cases performed by each of these surgeon and hospital volume strata we had established.
RESULTS
SSLR analysis of cost by annual surgeon THA volume produced stratifications at: 0–73 (low), 74–123 (medium), and 124 or more (high) (Figure 1). Analysis by annual hospital THA volume produced stratifications at: 0–121 (low), 122–309 (medium), and 310 or more (high) (Figure 2). Hospital costs decreased significantly (P < .05) in progressively higher volume stratifications. The largest proportion of THA cases are performed at high-volume hospitals (48.6%); however, low-volume surgeons perform the greatest share of these cases (44.6%) (Figure 3).
CONCLUSIONS
Our study establishes economies of scale in total hip arthroplasty by demonstrating a direct relationship between volume and cost reduction. High volume hospitals are performing the greatest proportion of total hip arthroplasties; however, low volume, surgeons perform the largest share of these cases, which highlights a potential area for enhanced value in the care of patients undergoing total hip arthroplasty.
