Variation in Surgeon Proficiency Scores and Association With Digit Replantation Outcomes

Importance: Risk-adjusted variation in surgeon outcomes has been traditionally explained by surgeon volume and hospital infrastructure, yet it is unclear how a surgeon's operative proficiency directly contributes to their patients' outcomes. Objective: To assess the variation of surgeons' operative proficiency and investigate its association with surgical outcomes. Design, Setting, and Participants: This case series was a retrospective analysis of all digit replantations and revascularizations at a single US university medical center between January 2000 and August 2020. Surgeons were assigned a proficiency score based on the expected procedure difficulty and outcomes from a sample of their cases. Surgeon proficiency scores were then used to determine associations with outcomes from subsequent cases. The expected difficulty of each case was calculated using a novel scoring system that applied pooled relative risks from a meta-analysis of risk factors for replantation and revascularization failure. Exposures: Digit replantation and revascularization. Main Outcomes and Measures: Digit survival at 1-month follow up (case success) and number of complications. Results: A total of 145 patients and 226 digits were treated by 11 surgeons with training in hand or microsurgery (mean SD age, 41.9 15.2 years; 204 90% men); there were 116 replantations and 110 revascularizations. Surgeon proficiency scores ranged from 1.3 to 5.7, with a mean (SD) of 3.4 (1.4). Case success rates among surgeons varied from 20.0% to 90.5%, with a mean (SD) of 64.9%. Higher proficiency scores were associated with fewer case failures: each point increase was associated with 40% decreased odds of failure (odds ratio, 0.60; 95% CI, 0.38-0.94). Every 3-point increase in proficiency score was associated with 1 less complication (effect estimate, -0.29; 95% CI, -0.56 to 0.02). Surgeon proficiency score had a greater association with case failure than surgeon volume (16.7% vs 12.0%). The final model's association with case failure had an area under the receiver operating characteristics curve of 0.93. Conclusions and Relevance: Operative proficiency varied widely among practicing surgeons and accounted for 17% of estimative ability for success of digit replantation and revascularization. Greater surgeon proficiency was associated with better outcomes, indicating that the value of surgical care may be optimized by improving surgeon proficiency.