Hot-spot analysis of malignant neoplasm of the trachea, bronchus and lung in the US

Background: Geographic maps treating counties as single entities may obscure age-race-gender specific outcomes influenced by regional structures. Methods: Hot spot analysis (Gelis-Ord-Gi* statistic) was used to map age-adjusted (25+ years), race-ethnicity-gender-specific mortality from malignant neoplasm of the trachea, bronchus, and lung in the US (1999-2009). Input was from the public CDC WONDER Compressed Mortality file. Results: Two major clusters were identified for white, non-Hispanic men (GIZ-scores = 9.7 to 14.3), one centered in Appalachia and one encompassing counties in northern Florida and southern Georgia. White, non-Hispanic women (GIZ scores = 8.3 to 13.8) shared the Appalachian cluster. Rates for non-Hispanic black men (GIZ scores = 6.5 to 8.7) were focused in areas the Mississippi Delta north of New Orleans, and also extending westward to AR and TX. No such cluster was found for non-Hispanic black women, although scattered hot spots (GIZ scores = 6.0 to 9.5) were found throughout KY, MO, IL, IN, and OH. The most prominent focus for both Hispanic women (GIZ scores = 1.6 to 2.8) and men (GIZ scores 1.9 to 3.1) was in central FL. Conclusions: Distinct geographic patterns of mortality from malignant neoplasm of the trachea, bronchus, and lung were observed, depending on race, gender and ethnicity, possibly indicating different causal pathways. Multivariable analyses to estimate possible relationships between hot spots and contextual social and demographic determinants, risky behaviors, and environmental exposures – including comparisons between hot spots and other areas -- are underway. Analytic epidemiologic study will be needed to elucidate etiologic factors.