MMS hotspots: a cross-sectional comparison of U.S. counties with and without Mohs micrographic surgery

Healthcare access greatly impacts skin cancer diagnosis and mortality rates. Recognition of current disparities in Mohs micrographic surgery (MMS) access can assist future policy and clinical decisions to correct them. For the years 2014-2018, the CPT codes for MMS (17,311 and 17,313) were counted on a per county level across the United States per the Medicare Centers for Medicare & Medicaid Services (CMS) Medicare Prescriber Database. Any county with 0 MMS CPT codes recorded were classified as "without MMS cases." MMS "hotspots" were identified as counties that possessed a high average number of MMS cases compared to the national average, while also being surrounded by counties that possessed a low average number of MMS cases compared to the national average. Three thousand eighty-four counties in the United States were analyzed; 785 (25%) counties were designated as "with MMS cases" and 2301 (75%) "without MMS cases." There were no significant differences in age, ethnicity distribution, or cost per enrollee between the two designations. 74% of counties with MMS cases were considered urban, while only 25% of those without cases were urban (p < 0.01). The median household income was markedly higher in counties with MMS cases ($71,428 vs. $58,913, p < 0.01). With respect to education, more individuals in counties with MMS cases possessed their General Education Development (GED) (89% vs. 86%, p < 0.01) or a college degree (30% vs. 19%, p < 0.01). Forty-nine counties were considered MMS "hotspots." The density of MMS procedures varies greatly based on geography, maintaining the urban-rural disparity matched by the distribution of MMS surgeons. Additionally, there remains a wide income and educational gap between counties with and without MMS. Identifying MMS hotspots may facilitate further investigation into potential surgical access disparities.