Colorectal cancer screening among obese versus non-obese patients in primary care practices

Obesity is associated with increased colorectal cancer incidence and mortality. Previous studies using telephone survey data showed that obese women were less likely to receive colorectal cancer screening. It is unknown if this is true among patients in primary care practices.

Retrospective chart reviews were conducted in 2003-2004 of men and women in 22 suburban New Jersey and Pennsylvania primary care practices. Data from patients age 50 years and over (n=1297) were analyzed using hierarchical logistic regression. The outcome measure was receipt of colorectal cancer screening (fecal occult blood test within 1 year, sigmoidoscopy within 5 years, colonoscopy within 10 years, or barium enema within 5 years) among obese and non-obese patients.

Overall, 39% of patients were obese and 29% received colorectal cancer screening. After controlling for age, gender, total number of co-morbidities, number of visits in the past 2 years, and number of years in the practice, obese patients had 25% decreased odds of being screened for colorectal cancer compared to non-obese patients (OR 0.75, 95% CI, 0.62-0.91). The relationship of obesity and colorectal cancer screening did not differ according to gender. Number of visits (OR 1.04, 95% CI, 1.01-1.06) and male gender (OR 1.53, 95% CI, 1.19-1.97) was associated with increased odds of receiving colorectal cancer screening.

Identification of physician and patient barriers to colorectal cancer screening is needed, particularly in obese patients, so that effective interventions may be developed to increase screening in this high-risk group.