Seminar Hospital Volume and Knee Replacement Outcomes: Implications for Workforce Participation

Abstract

Improving the quality of surgical care is a key priority for health systems. Hospital volume is often linked to patient outcomes, typically explained by either a “practice makes perfect” effect, where experience improves performance, or “selective referral,” where hospitals with better outcomes attract more patients. Understanding which mechanism dominates is crucial for designing effective healthcare policies. Building on this motivation, we analyse whether hospital volume predicts variation in patient out- comes after primary knee replacement in Norway. We evaluate recovery along two dimensions: labour market outcomes—measured through sick leave duration and post-operative income—and clinical out- comes, defined by 30-day emergency readmissions and revision surgery within two years. To address potential endogeneity due to the elective nature of the procedure, we instrument hospital volume using predicted patient choice from a conditional logit model and estimate hospital fixed-effects regressions controlling for observable characteristics. Across specifications, we find no evidence that higher volume improves outcomes. Estimated effects are small, inconsistent, and clinically negligible, even under substantial increases in volume. Hospitals vary considerably in both clinical and labour-market performance, yet these differences are unexplained by volume, suggesting that organisational practice, surgeon experience, or resource pathways are more relevant drivers of outcome variation