Distance to diagnosing provider as a measure of access for patients with melanoma

Objective: To examine the effect of travel distance and other sociodemographic factors on access to a diagnosing provider for patients with melanoma. Design: Analysis was performed of all incident cases of melanoma in 2000 from 42 North Carolina counties. Setting: Academic research. Participants: Patients and providers from 42 North Carolina counties were geocoded to street address. Main Outcome Measures: Associations between Breslow thickness and clinical and sociodemographic factors (age, sex, poverty rate, rurality, provider supply, and distance to diagnosing provider) were examined. Results: Of 643 eligible cases, 4.4% were excluded because of missing data. The median Breslow thickness was 0.6 mm (range, 0.1-20.0 mm). The median distance to diagnosing provider was 8 miles (range, 0-386 miles). For each 1-mile increase in distance, Breslow thickness increased by 0.6% (P=.003). For each 1% increase in poverty rate, Breslow thickness increased by 1% (P = .04). Breslow thickness was 19% greater for patients aged 51 to 80 years than for those aged 0 to 50 years (P = .02) and was 109% greater for patients older than 80 years than for those aged 0 to 50 years (P <.001). Sex, rurality, and supply of dermatologists were not associated with Breslow thickness. Conclusions: For patients with melanoma, distance to the diagnosing provider is a meaningful measure of access that captures different information than communitylevel measures of rurality, provider supply, and socioeconomic status. Future work should be targeted at identifying factors that may affect distance to diagnosing provider and serve as barriers to melanoma care.