Area-level factors associated with spatial variation of prostate cancer incidence for black men

Abstract

Purpose: Black men are disproportionately affected by prostate cancer (CaP) compared to any other racial/ethnic groups within the United States. Identifying CaP hotspots along with associated local area-level risk factors is crucial to tackling the significant burden of CaP and the disparity seen in Black men. The objective of this study was to determine the scope of geographical variation in CaP incidences and to assess the degree to which this variation is associated with county-level risk and protective factors.

Methods: The study population was Black men diagnosed with prostate cancer between 2006-2010 in Florida. County-level CaP incidence rates were computed as the ratios of the numbers of new CaP cases diagnosed between 2006 and 2010 to the corresponding 2000 US census population of Black men 20 and over years old data (US Census 2000). Other county-level environmental and health care factors were also obtained. A random effects Poisson model and Geographical Information System (GIS) were used to map and assess the spatial patterns of CaP incidences in 67 Florida counties. These statistical techniques involved a Bayesian approach for estimating the underlying county-specific CaP risk since the data are very sparse.

Results: The findings showed that an increasing CaP incidence of Black Men in Florida  was significantly associated with an increasing unemployment rate ( ₂     with 95% CI: (.0025, .2703), does not include zero suggesting significance) and with increasing number of physicians per capita after controlling for other county characteristics. There was a negative association between poverty and CaP incidence. Regarding spatial distribution of CaP incidence, we observed that there are clustering and hotspots of high CaP incidence rates in Palm Beach county in South Florida, and Alachua and Marion counties in north Florida.

Conclusion: Our findings showed that indicators of socioeconomic status and accessibility of health care services such as poverty, unemployment and health care providers are important variables that explain spatial variation of prostate cancer incidence rates of Black Men. Better understanding of such risk factors and identifying specific counties with a disproportionate burden of CaP disease may help formulate targeted interventions and resource allocation by state and local public officials