Evaluation of a Peer-to-Peer Data Transparency Intervention for Mohs Micrographic Surgery Overuse

IMPORTANCE: Mohs micrographic surgery (MMS) is a skin cancer treatment that uses staged excisions based on margin status. Wide surgeon-level variation exists in the mean number of staged resections used to treat a tumor, resulting in a cost disparity and question of appropriateness. OBJECTIVE: To evaluate the effectiveness of a behavioral intervention aimed at reducing extreme overuse in MMS, as defined by the specialty society, by confidentially sharing stages-per-case performance data with individual surgeons benchmarked to their peers nationally. DESIGN, SETTING, AND PARTICIPANTS: This nonrandomized controlled intervention study included 2329 US surgeons who performed MMS procedures from January 1, 2016, to March 31, 2018. Physicians were identified using a 100% capture of Medicare Part B claims. The intervention group included physicians affiliated with the American College of Mohs Surgery, and the control group included physicians not affiliated with the American College of Mohs Surgery. INTERVENTIONS: Individualized performance reports were delivered to all outlier surgeons, defined by the specialty society as those with mean stages per case 2 SDs above the mean, and inlier surgeons in the intervention group. MAIN OUTCOMES AND MEASURES: The primary outcome was surgeon-level change in mean stages per case between the prenotification (January 2016 to January 2017) and postnotification (March 2017 to March 2018) periods. A multivariable linear regression model was used to evaluate the association of notification with this surgeon-level outcome. The surgeon-level metric of mean stages per case was not risk adjusted. The mean Medicare cost savings associated with changes in practice patterns were calculated. RESULTS: Of the 2329 included surgeons, 1643 (70.5%) were male and 2120 (91.0%) practiced in metropolitan areas. In the intervention group (n = 1045), 53 surgeons (5.1%) were outliers; in the control group (n = 1284), 87 surgeons (6.8%) were outliers. Among the outliers in the intervention group, 44 (83%) demonstrated a reduction in mean stages per case compared with 60 outliers in the control group (69%; difference, 14%; 95% CI of difference, −1 to 27; P = .07). There was a mean stages-per-case reduction of 12.6% among outliers in the intervention group compared with 9.0% among outliers in the control group, and outliers in the intervention group had an adjusted postintervention differential decrease of 0.14 stages per case (95% CI, −0.19 to −0.09; P