Are gender differences in colorectal cancer screening rates due to differences in self-reporting?

Objective: Studies have found that women are less likely than men to undergo colorectal cancer (CRC) screening. While one source of these disparities may be gender differences in barriers and facilitators to screening, another may be differences in reporting bias. Method: In this study of 345 male and female veterans, conducted in 2006 in Minneapolis, MN, we examined CRC screening adherence rates by gender using medical records and self-report and assessed whether any differences were due to reporting bias. Results: We found a significantly higher rate of colonoscopy use among men when using self-report data, but no significant differences in either overall or test-specific screening adherence when using medical record data. Analyses examining the prevalence and determinants of concordance between self-report and medical records screening revealed that compared to women, men were less accurate in reporting sigmoidoscopy and colonoscopy and over-reported screening by colonoscopy. Men were also more likely to have missing self-report data and how missing data were handled affected differences in screening behavior. Accuracy in screening behavior was not explained by demographic variables, good physical or mental health, or physician recommendation for screening. Conclusions: Reported gender disparities in CRC screening adherence may be a result of reporting bias.