Risk Factors That Are Associated With Outliers in Mohs Micrographic Surgery in the National Medicare Population, 2018.

Background: Physician variation exists in the mean number of stages performed per Mohs micrographic surgery (MMS) case. Physicians who are outliers in medical practice may be leading to a higher health care cost burden.

Objective: To identify factors that influence being a high outlier in the mean stages per MMS case.

Materials And Methods: The study comprised a retrospective analysis of 2018 data from physicians who billed Medicare Part B for Current Procedural Terminology (CPT) 17311 and 17312 (MMS of the head, neck, hands, feet, or genitalia) and/or CPT 17313 and 17314 (MMS of the trunk, arms, or legs).

Results: For CPT 17311 and 17312, the odds ratio for being an outlier for a physician in a solo practice relative to a multiphysician facility is 2.4 (1.6-3.8), for a physician who is not an American College of Mohs Surgery (ACMS) member relative to a ACMS member is 2.0 (1.2-3.2), and for a practice located in the West, Northeast, and South is 7.7 (2.8-21.6), 6.2 (2.1-18.6), and 1.8 (0.6-5.4), respectively, relative to in the Midwest.

Conclusion: Physicians who are practicing solo, practicing in the West or Northeast, and are not ACMS members are more likely to be a high outlier in the mean stages per MMS case.