Colorectal Cancer Screening Completion Among Individuals With and Without Mental Illnesses: A Comparison of 2 Screening Methods

Purpose: Cancer mortality is worse among people with psychiatric disorders. The purpose of this study was to compare facilitators and rates of colorectal cancer (CRC) screening between people with and without mental illnesses. Design: We conducted a secondary analysis using data from a general population cohort study (N = 92 445) that assessed effects of 2 types of CRC screening test kits—guaiac fecal occult blood testing (gFOBT) and fecal immunochemical testing (FIT)—on CRC screening completion. Setting: The setting was a health system that served approximately 485 000 members in urban and suburban Oregon and Washington. Participants: Participants were health system members, categorized by mental illness diagnosis (psychotic disorders, non-psychotic unipolar depression, and no mental illness), who were age-eligible, at average risk of CRC, and were at least 366 days past their last gFOBT with no evidence of other CRC screening. Measures: The outcome was time until completion of CRC screening. Analysis: We used Cox proportional hazard models. Results: FIT reduced CRC screening barriers for all the groups. Compared to people without mental illness diagnoses, those with psychotic disorders were equally likely to screen using FIT (hazard ratio [HR] =.95, p =.679) and those with depression were more likely (HR = 1.17, p =.006). Conclusions: FIT can improve CRC screening rates among people with mental illnesses, particularly depression.