Association of Index Adopter Characteristics With Peer Surgeon Adoption of Robotic Bariatric Surgery.

IMPORTANCE: Robotic surgery adoption in bariatric surgery has expanded rapidly, yet whether early adopter performance influences subsequent peer adoption remains unknown. OBJECTIVE: To examine the association between index adopter performance characteristics and peer surgeon adoption of robotic bariatric surgery. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using the Michigan Bariatric Surgery Collaborative, a statewide quality improvement registry. Adults undergoing primary laparoscopic or robotic bariatric surgery between 2006 and 2025 were included. Peer surgeons were non-index surgeons at robotic-program sites, each assigned to their earliest robotic site. EXPOSURES: Index adopter characteristics: high surgical volume, low complication rate, fast learning curve, and a composite quality indicator. MAIN OUTCOMES AND MEASURES: Primary outcome was peer surgeon adoption of robotic surgery. Analyses included multivariable logistic regression with sensitivity analyses using propensity score matching, inverse probability weighting, and causal forest methods. RESULTS: The cohort included 87,068 procedures by 121 surgeons at 41 hospitals. Among 106 peer surgeons, 50 (47.2%) adopted robotics (median, 1730 days; IQR, 652-2543). High-volume index adopters were associated with lower peer adoption (adjusted OR, 0.30; 95% CI, 0.09-0.84; P = .03), confirmed by inverse probability weighting (OR, 0.37; P = .04) and causal forest analysis (ATE, - 0.26; P = .02). Results were directionally consistent across all 7 approaches. CONCLUSIONS AND RELEVANCE: High-volume index adopter performance was associated with lower peer adoption, consistent with a crowding-out hypothesis. Promoting technology diffusion may require focusing on equitable robotic resource access rather than peer influence from high-performing early adopters.