The interrelationships between and contributions of background, cognitive, and environmental factors to colorectal cancer screening adherence

Objectives: We examined the interrelationships between and contributions of background, cognitive, and environmental factors to colorectal cancer (CRC) screening adherence. Methods: In this study, 2,416 average risk patients aged 50-75 from 24 Veterans Affairs medical facilities responded to a mailed survey with phone follow-up (response rate 81%). Survey data (attitudes, behaviors, demographics) were linked to facility (organizational complexity) and medical records data (diagnoses, screening history). Patients with a fecal occult blood test within 15 months, sigmoidoscopy or barium enema within 5.5 years, or colonoscopy within 11 years of the survey were considered adherent. Logistic regressions estimated the association between adherence and background, cognitive, and environmental factors. Deviance ratios examined interrelationships between factors. Population attributable risks (PAR) were used to identify intervention targets. Results: The association of background factors with adherence was partially explained by cognitive and environmental factors. The association of environmental factors with adherence was partially explained by cognitive factors. Cognitive and environmental factors contributed equally to adherence. Factors with the highest PARs for non-adherence were age 50-64, less than two comorbidities, and lack of physician recommendation. Conclusions: Efforts to increase physician screening recommendations for younger, healthy patients at facilities with the lowest screening rates may improve CRC adherence in this setting.