Validation of scales to measure benefits of and barriers to colorectal cancer screening

Participating in screening for colorectal cancer can significantly decrease mortality from this disease. Although the health belief model constructs of perceived benefits and barriers have been related to other cancer screening behaviors, benefits and barriers to fecal occult blood testing (FOBT) have not been measured consistently, and little is known about these variables in relation to flexible sigmoidoscopy and colonoscopy. The purpose of this study was to establish the psychometric properties of six scales measuring benefits and barriers related to screening for colorectal cancer, including FOBT. flexible sigmoidoscopy, and colonoscopy. Reliability coefficients for the scales ranged from .65 to .77, Construct validity was established using exploratory factor analyses with results confirming unidimensionality of constructs. Construct validity was further assessed by testing theoretical relationships among benefits, barriers, and screening behaviors. Results of analyses of variance were consistent with theoretical predictions: Perceived benefits were higher and perceived barriers were lower for people who had undergone sigmoidoscopy or colonoscopy compared with people who had not had these tests.