Relationship between latitude and melanoma incidence: international evidence.

We investigate the relationship between latitude and incidence of melanoma among Whites in different age groups using data from different continents. Relevant data for Whites were obtained for 59 regions around the world. A statistical analysis was carried out using regional dummy variables to eliminate spurious statistical correlation due to clustering. Simple correlation between latitude and incidence of melanoma is strongly negative for almost all age groups. However, once the regional dummies were introduced in the analysis, the relation between latitude and incidence rates disappeared for all age groups but the explanatory power of the regression equation increased substantially.