Underuse of screening sigmoidoscopy and colonoscopy in a large cohort of US adults

Objectives. We examined the prevalence of endoscopy (sigmoidoscopy or colonoscopy) by indication and by demographic and lifestyle factors. Methods. We analyzed cross-sectional data collected in 1997 from participants aged 50 years and older in the Cancer Prevention Study (CPS) II Nutrition Cohort. Results. Fifty-eight percent of men and 51% of women reported ever having undergone endoscopy; only 42% of men and 31% of women reported endoscopy for screening rather than for disease diagnosis or follow-up. Prevalence varied by demographic and lifestyle factors. Conclusions. Efforts to increase colorectal cancer screening need to target women, all persons aged 50-64 years, and those with colorectal cancer risk factors. Future studies should distinguish endoscopy for screening from procedures for disease diagnosis and follow-up to avoid overestimating screening compliance.