Use of Colorectal Cancer Tests --- United States, 2002, 2004, and 2006
Colorectal cancer is the second-leading cause of cancer-related deaths in the United States among cancers that affect both men and women (1). The U.S. Preventive Task Force and other national organizations recommend that persons aged >50 years at average risk be screened for colorectal cancer using one or more of the following methods: fecal occult blood testing (FOBT) every year, sigmoidoscopy or double-contrast barium enema every 5 years, or colonoscopy every 10 years (2--4). To estimate rates of use of colorectal cancer tests and to evaluate changes in test use, CDC compared data from the 2002, 2004, and 2006 Behavioral Risk Factor Surveillance System (BRFSS) surveys (5). This report describes the results of that comparison, which indicated that the proportion of respondents aged >50 years reporting use of FOBT and/or sigmoidoscopy or colonoscopy increased overall from 2002 to 2006; however, certain populations, such as racial/ethnic minorities and those who reported no health insurance coverage, had lower prevalence of testing. Specific measures to increase colorectal cancer screening and address disparities in screening are needed.
BRFSS is a state-based, random-digit--dialed telephone survey of the noninstitutionalized, U.S. civilian population aged >18 years. Survey data were available for the 50 states (except for Hawaii in 2004) and the District of Columbia. The median state response rate, based on Council of American Survey and Research Organizations (CASRO) guidelines, was 58.3% in 2002, 52.7% in 2004, and 51.4% in 2006. Respondents who refused to answer, had a missing answer, or did not know the answer to a question were excluded from analysis of that specific question. Of persons aged >50 years who responded, approximately 3% of 108,028 were excluded from 2002 results, approximately 3% of 146,794 persons were excluded from 2004 results, and approximately 4.5% of 195,318 were excluded from 2006 results.
Survey questions and response options were identical for all three survey years. Respondents aged >50 years were asked if they had ever used a "special kit at home to determine whether the stool contains blood (FOBT)," whether they had ever had "a tube inserted into the rectum to view the colon for signs of cancer or other health problems (sigmoidoscopy or colonoscopy)," and when these tests were last performed. For this report, sigmoidoscopy and colonoscopy are described as "lower endoscopy." Percentages were estimated for persons aged >50 years who reported receiving an FOBT within 1 year preceding the survey or lower endoscopy within 10 years preceding the survey. Because BRFSS does not differentiate between sigmoidoscopy and colonoscopy, the surveillance period used was 10 years, the recommended interval for colonoscopy for persons at average risk. Aggregate percentages and 95% confidence intervals were calculated. Data were weighted to the sex, racial/ethnic, and age distribution of each state's adult population using intercensal estimates and were age standardized to the 2006 BRFSS population aged >50 years. Differences in prevalence were considered statistically significant if confidence intervals did not overlap. The Wald F-test was used to determine significance for differences across the three surveys.
In 2006, 60.8% of respondents aged >50 years reported having had an FOBT within 1 year preceding the survey or lower endoscopy within 10 years preceding the survey, compared with 56.8% in 2004 and 53.9% in 2002 (Table 1). Across all survey years, the proportion of persons aged >50 years who reported having had either test within recommended intervals was greater among those aged >65 years compared with those aged 50--64 years. The proportion also was greater for whites compared with all other races; non-Hispanics compared with Hispanics; and persons with health insurance compared with those with no health insurance. The percentage of positive responses also increased with increasing education level and with increasing household income. Although a greater proportion of men compared with women had a colorectal cancer test in all three survey years, this difference was not statistically significant in 2006.
By state, the proportion of respondents who reported having had an FOBT within 1 year preceding the survey or lower endoscopy within 10 years preceding the survey in 2006 ranged from 51.8% in Mississippi to 70.5% in Connecticut (Table 2). The proportion of respondents who reported having had an FOBT within 1 year preceding the survey ranged from 6.8% in Utah to 22.7% in the District of Columbia and Maine. The proportion of respondents who reported a lower endoscopy within 10 years preceding the survey ranged from 46.7% in Mississippi to 66.7% in Minnesota.
The proportion of respondents who reported never being tested decreased from 34.2% in 2002, to 32.2% in 2004, and to 29.5% in 2006 (Figure). The proportion of respondents aged >50 years who reported having had an FOBT within 1 year of the survey declined from 21.6% in 2002, to 18.5% in 2004, and to 16.2% in 2006. In contrast, the proportion of respondents who reported having had a lower endoscopy within 10 years preceding the survey increased from 44.8% in 2002, to 50.1% in 2004, and to 55.7% in 2006.
Reported by: DA Joseph, MD, SH Rim, MPH, LC Seeff, MD, Div of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, CDC.
The findings in this report indicate that overall use of colorectal cancer tests increased from 2002 to 2006. Although this increase is encouraging, disparities persist in colorectal cancer test use. Colorectal cancer test use increased among racial/ethnic minorities, those without health insurance, those with annual household incomes <$35,000, and those with less than a high school education; however, these groups had a substantially lower prevalence of colorectal cancer test use than did other groups surveyed. Factors that might contribute to disparities in colorectal cancer test use include lack of awareness of the need for screening, lack of recommendation for screening from a physician, lack of health insurance, and lack of a usual source of health care (6,7).
Previous studies have documented a greater prevalence of colorectal cancer test use among men than women (6,7). Data in this report suggest that the gap in prevalence between men and women is closing.
Respondents aged >65 years were found to have a greater prevalence of colorectal cancer test use compared with those aged 50--64 years, which might be associated with the availability of Medicare coverage for colorectal cancer screening starting at age 65 years (6,7). Previous studies have indicated that colorectal cancer testing has increased since 2000 (7). Multiple factors might have contributed to the increase in colorectal cancer test use. For example, Medicare coverage of screening colonoscopy (starting in 2001) contributed to increased use of colonoscopy in the Medicare population (7). Increased public awareness of the importance of screening (5) and adoption of the Health Plan Employer Data and Information Set (HEDIS) measure (in 2004) that encourages health plans to cover colorectal screening tests also might have contributed to the increase in test use.* In addition, a number of state initiatives support increased test use, including a statewide social marketing campaign implemented by Maine's Comprehensive Cancer Control Program, a statewide endoscopy screening program in Colorado funded by the state tobacco tax, and New York State's Colorectal Cancer Screening and Prostate Initiative Program, which provides colorectal cancer screening to uninsured or underinsured residents. New York also passed the Colon-Prostate Treatment Act in 2006, which provides funds for treatment of colorectal cancer cases detected through the state screening program.
The reported use of FOBT declined steadily over the study period, whereas the reported use of lower endoscopy increased. These changes might have been driven by patient or physician preference for lower endoscopy over FOBT and increased availability of insurance coverage for screening colonoscopy (8,9). Variations in prevalence of test use by state might result from variations in demographic characteristics, health insurance coverage, and availability of providers to perform endoscopy.
The findings in this report are subject to at least five limitations. First, the results might overestimate actual colorectal cancer screening tests because BRFSS does not determine the indication for the test (screening versus diagnostic use). Second, assessment of use of lower endoscopy within 10 years included persons who had a sigmoidoscopy more than 5 years preceding the survey, which is outside the screening recommendation. Third, only persons with landline telephones are represented in the analysis. Fourth, responses are self-reports and not validated by medical record review. Finally, the survey response rate was low for all three survey years.
To address disparities in colorectal cancer screening rates and to improve access to underserved populations, CDC established a colorectal cancer screening demonstration program in August 2005 for persons with inadequate or no insurance coverage for colorectal cancer screening. These programs are located in Baltimore, Maryland; St. Louis, Missouri; Nebraska (statewide); Suffolk County, New York; and Clallam, Jefferson, and King counties, Washington; they vary in design and screening test selection. Each program is designed for all low-income U.S. men and women aged >50 years, and two of the programs are targeted to racial/ethnic minorities. CDC is conducting a detailed evaluation of the programs, including a multiple case study, a cost assessment, and an evaluation of clinical outcomes. CDC also provides funds to 21 state programs to implement specific colorectal cancer control strategies identified in their statewide cancer control plans.§
Screening reduces colorectal cancer incidence and mortality (2). The coordinated efforts by CDC, state and local health departments, and the medical community to address barriers to and disparities in screening must be sustained so that the burden of this disease can be reduced in all persons.
This report is based, in part, on data contributed by state BRFSS coordinators.
* Available at http://www.ncqa.org/tabid/59/default.aspx.
Information about Article 5: Title 11: Sections 364-I and 366 available at http://public.leginfo.state.ny.us/menugetf.cgi.
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Date last reviewed: 3/13/2008