Effects of physician supply on melanoma incidence and mortality in Florida

Increasing supplies of dermatologists and family physicians have been associated with earlier detection of malignant melanoma. We investigated whether physician supply was similarly related to incidence and mortality rates of malignant melanoma. Using the state tumor registry, we determined melanoma incidence and mortality rates for the years 1993 to 1995 for each Florida county. We measured physician supply for each Florida county using data from the 1994 American Medical Association Physician Masterfile. Multiple linear regression analysis was used to determine relationships between physician supply and melanoma incidence and mortality rates, controlling for other county-level characteristics. Among male patients, an increasing supply of family physicians was associated with higher melanoma incidence and lower melanoma mortality. Increasing supplies of dermatologists were associated with lower overall melanoma mortality rates, and increasing supplies of general internists were associated with higher overall melanoma mortality. We found that melanoma incidence and mortality rates varied substantially among Florida's 67 counties, and that differences in physician supply explained some of this variability. Further study is needed to confirm these findings and to elucidate possible mechanisms that would account for these associations.