LAUSR

INTRODUCTION Obesity is a major risk factor for colorectal cancer (CRC), particularly among men. The purpose of this study was to characterize the prevalence of guideline-adherent CRC screening among obese adults using nationally representative data, assess trends in screening strategies, and identify obesity-specific screening barriers. METHODS Data from 8,550 respondents aged 50-75 years in the 2010 National Health Interview Survey, representing >70 million adults, were analyzed in 2015 using multivariable logistic regression. Prevalence of guideline-adherent CRC screening, endoscopic versus fecal occult blood test screening, and reasons for non-adherence were compared across BMI categories. RESULTS Obese class III men (BMI ≥40), compared with normal-weight men, were significantly less likely to be adherent to screening guidelines (38.7% vs 55.8%, AOR=0.35, 95% CI=0.17, 0.75); less likely to have used an endoscopic test (36.7% vs 53.0%, AOR=0.37, 95% CI=0.18, 0.79); and had a trend toward lower fecal occult blood test use (4.2% vs 8.9%, AOR=0.42, 95% CI=0.14, 1.27). Among women, odds of guideline adherence and use of different screening modalities were similar across all BMI categories. Reasons for non-adherence differed by gender and BMI; lacking a physician screening recommendation differed significantly among men (29.7% obese class III vs 15.4% non-obese, p=0.04), and pain/embarrassment differed significantly among women (11.6% obese class III vs 2.6% non-obese, p=0.002). CONCLUSIONS Despite elevated risk, severely obese men were significantly under-screened for CRC. Addressing the unique screening barriers of obese adults may promote screening uptake and lessen disparities among the vulnerable populations most affected by obesity.