Disparities in Colon Cancer Screening Remain Among Medicare Patients

Armen Hareyan's picture

Although Medicare coverage for colorectal cancer screening has increased, there are still significant disparities in screening practices by ethnicity, sex, age, education and income level, according to a report in the February 12, 2007 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

Colorectal cancer is the third most common cancer affecting men and women in the United States with approximately 145,290 new cases in 2005, according to background information in the article. "There is evidence that screening for colorectal cancer decreases incidence and mortality from the disease," the authors write.


Ashwin N. Ananthakrishnan, M.D., M.P.H., and colleagues at Medical College of Wisconsin, Milwaukee, examined the Medicare physician billing claims file for New York, Florida and Illinois for 2002 and 2003 to identify the rates of colon cancer screening tests in the population at average risk for the disease. Data from the U.S. Census and the Medicare database were used to verify the sex, race or ethnicity, age and social characteristics of the population, such as the educational achievement and per capita income level of each patient based on their ZIP codes of residence. The type of test screening completed by each patient (fecal occult blood test [FOBT], flexible sigmoidoscopy, double contrast barium enema [DCBE] and colonoscopy) was also noted.

A total of 596,470 Medicare recipients were included in the study population with an approximately even number of patients in each age category (65 to 69, 70 to 74, 75 to 79, and 80 or older) and more women than men in all three states. The population was 89.5 percent white, 7 percent African American and 2.1 percent Hispanic. An estimated 18.3 percent of the sample population had been screened for colon cancer during the study period. "A larger percentage of the population had undergone a screening colon test in Florida (21.5 percent) compared with Illinois (16.6 percent) and New York (16.2 percent).

"Blacks (9.7 percent) and Hispanics (8.1 percent) had lower rates of colon cancer screening compared with whites (19.3 percent)," the authors note. "Individuals living in ZIP codes with a higher per capita income were more likely to undergo a colon screening test than were those living in ZIP codes with a lower per capita income (21 percent and 14.6 percent in the highest and lowest tertiles respectively)." The study also found that women were less likely to undergo an invasive screening test or colonoscopy and that residing in a ZIP code with a greater amount of high school graduates was associated with undergoing colon cancer screening.

"Despite expanded Medicare coverage, there are still significant disparities in colorectal cancer screening practices," the authors conclude. "Further research is needed to determine the basis for the observed ongoing disparities to develop interventions to reduce and eliminate these differences."