Mental Illness Is Not Associated with Adherence to Colorectal Cancer Screening: Results from the California Health Interview Survey

Colorectal cancer is the second leading cause of cancer-specific death in the USA. Evidence suggests people with mental illness are less likely to receive preventive health services, including cancer screening. We hypothesized that mental illness is a risk factor for non-adherence to colorectal cancer-screening guidelines. We analyzed results of the 2007 California Health Interview Survey to test whether mental illness is a risk factor for non-adherence to colorectal cancer-screening recommendations among individuals age 50 or older (N = 15,535). This cross-sectional dataset is representative of California. Screening was defined as either fecal occult blood testing during the preceding year, sigmoidoscopy, or colonoscopy during the preceding 5 years. Mental illness was identified using the Kessler K6 screening tool. Associations were evaluated using weighted multivariate logistic regressions. Mental illness was not associated with colorectal cancer-screening adherence (OR 0.89; 95% CI 0.63-1.25). Risk factors for non-adherence included being female (OR 1.25; 95% CI 1.09-1.44), delaying accessing health care during the previous year (OR 1.89; 95% CI 1.56-2.29). Unlike previous studies, this study did not find a relationship between mental illness and colorectal cancer-screening adherence. This could be due to differences in study populations. State-specific healthcare policies involving care coordination for individuals with mental illness could also influence colorectal cancer-screening adherence in California.