BACKGROUND: Obesity is associated with a higher incidence of colorectal cancer and increased colorectal cancer mortality. Obese women
are less likely to undergo breast and cervical cancer screening than nonobese women. It is not known whether obesity is associated
with a lower likelihood of colorectal cancer screening.
OBJECTIVE: To evaluate whether there is an association between body mass index (BMI) and rates of colorectal cancer screening. To examine
whether BMI-related disparities in colorectal cancer screening differ between men and women.
DESIGN AND SETTING: The Behavioral Risk Factor Surveillance System, a cross-sectional random-digit telephone survey of noninstitutionalized adults
conducted by the Centers for Disease Control and Prevention and state health departments in the 50 states and Washington,
DC in 1999.
PATIENTS: Survey respondents (N=52,886) between 51 and 80 years of age representing 64,563,332 U.S. adults eligible for colorectal cancer screening.
INTERVENTIONS AND MEASURMENTS: Adjusted rates of self-reported colorectal cancer screening with fecal occult blood testing within the past year or endoscopic
screening (sigmoidoscopy or colonoscopy) within the past 5 years.
RESULTS: The colorectal cancer screening rate was 43.8% overall. The rate of screening by FOBT within the last year or endoscopic
screening within the past 5 years was 39.5% for the morbidly obese group, 45.0% for the obese group, 44.3% for the overweight
group, and 43.5% for the normal weight group. The difference in screening rates was entirely attributable to differences in
BMI among women. After statistical adjustment for potential confounders, morbidly obese women were less likely than normal
weight women to be screened (adjusted rate difference, −5.6%; 95% confidence interval, −8.5 to −2.6). Screening rates among
normal weight, overweight, and obese women, and among men in different weight groups did not differ significantly.
CONCLUSIONS: Colorectal cancer screening rates among age-eligible persons in the U.S. are disturbingly low. Morbidly obese women, who
are at higher risk than others to develop and to die from colorectal cancer, are less likely to be screened. Efforts to increase
colorectal cancer screening are needed for all age-eligible groups, but should also include targeted screening of morbidly
obese women since they could reap substantial clinical benefits from screening.
Key words colorectal cancer screening - obesity - disparities - gender - quality of care
This work was presented at the 2002 annual national meeting of the Society of General Internal Medicine.
Dr. Rosen was supported by an AHRQ Health Services Research Fellowship at the Harvard School of Public Health, grant number
5 T32 HS00020-16.