Higher dermatologist density is associated with lower proportions of late-stage melanoma: An ecological study of the State Cancer Profiles.

Abstract

Cutaneous melanoma with regional or distant metastases (late-stage) is associated with worse survival than localized disease. Access to dermatologic care varies widely across the United States and may influence the stage at which melanoma is diagnosed. To examine the association between regional dermatologist density and the proportion of melanoma cases diagnosed at late-stage. This national ecological study used the State Cancer Profiles and Area Health Resource File data to assess proportions of late-stage melanoma and dermatologist counts per 100,000 population across National Cancer Institute Health Service Areas (HSAs) from 2017 to 2021. Five hundred fifty-seven HSAs met inclusion criteria. In multivariable analysis, higher dermatologist density was associated with significantly lower proportions of late-stage melanoma diagnosis. Compared with HSAs with no dermatologists, the odds of late-stage melanoma were reduced by 11% for >0-1 dermatologists per 100,000 population (OR = 0.89, P = .034), 11% for >1-2 (OR = 0.89, P = .020), 16% for >2-4 (OR = 0.84, P < .001), and 20% for >4 (OR = 0.80, P < .001). The ecological design limits causal inference and HSAs with low case counts were censored. Greater dermatologist density is associated with a lower proportion of melanoma cases diagnosed at a late-stage, underscoring the importance of improving access to specialty care.