Colorectal cancer screening adherence in a general population

Background: This article describes the self-reported colorectal cancer (CRC) screening adherence rates of adults, aged 50 years and older, living in five nonurban Minnesota counties. Methods: During the year 2000, 1693 eligible respondents, aged 50 years and older, from a randomly selected sample completed a survey assessing CRC screening adherence (similar to 86.3% response). The survey allowed differentiation between the four CRC screening modalities but did not differentiate between screening and diagnostic testing. Adjustment for nonresponse was performed using a version of Horvitz-Thompson weighting accounting for unknown eligibility. Results: 24.5% of respondents had a fecal occult blood test within 1 year of the survey, 33.8% had flexible sigmoidoscopy within 5 years, 29.3% had a colonoscopy within 10 years, and 13.7% had a barium enema within the last 5 years. Overall, 55.3% of respondents reported testing by any modality; thus, 44.7% were not adherent to screening guidelines. Conclusions: This study improves on previous attempts to characterize CRC screening adherence by assessing all four modalities of screening as recommended by current screening guidelines, by focusing on nonadherence, and by rigorously accounting for nonresponse. This study confirms that nearly half of the population remains unscreened by any method.