Original Article

Population-based Study of the Geographic Variation in Colon Cancer Incidence in Alabama: Relationship to Socioeconomic Status Indicators and Physician Density

Authors: Michèle P. L. Shipp, MD, DRPH, Renee Desmond, PHD, Neil Accortt, PHD, Reda J. Wilson, MPH, Mona Fouad, MD, MPH, Mohamad A. Eloubeid, MD, MHS


Objectives: The objective of this population-based study was to examine the relationship between race, socioeconomic characteristics (socioeconomic status, SES), physician density, and colon cancer incidence in Alabama.

Methods: Data for 5,788 colon cancer cases from 1996 to 1999 provided by the Alabama Statewide Cancer Registry are linked to county-level measures of SES, including median household income, percentage of high school graduates, percentage of families below poverty level, and occupational and health care factors. Poisson regression is used to model the predictors adjusting for age, gender, and race.

Results: Blacks had higher incidences of colon cancer compared with whites and presented with later stages (20.4% versus 14.8% for distant disease (P = 0.0089). After controlling for race, gender, and age at diagnosis, significant associations were detected between colon cancer incidence and higher education (RR = 1.10; 95% CI, 1.03–1.17), and increased number of physicians per 1,000 (RR = 1.14; 95% CI, 1.06–1.22). The county percentage of families below poverty is associated inversely with localized disease and positively with distant stage.

Conclusions: Colon cancer incidence varies geographically across Alabama and is positively related to aggregate SES factors, including education and physician density. A higher incidence of distant disease is related to black race and increased poverty. Health disparities in colon cancer across Alabama warrant further investigation.

Key Points

* Colon cancer incidence varies geographically across Alabama and is positively related to aggregate socioeconomic status factors, including education and physician density.

* Incidence of distant disease is related to black race and increased poverty.

* Health disparities across Alabama warrant further investigation.

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