Colorectal Cancer Screening and Yield in a Mailed Outreach Program in a Safety-Net Healthcare System

Background: Screening with fecal immunochemical testing (FIT) reduces colorectal cancer mortality; however, screening remains low in underserved populations. Mailed outreach, including an invitation letter, FIT, and test instructions, is an evidence-based strategy to improve screening. Aims: To examine screening completion and yield in a mailed outreach program in a safety-net healthcare system. Methods: We identified and mailed outreach invitations to patients due for screening in a large safety-net system between September 1, 2018, and August 31, 2019. We examined: (1) screening completion, the proportion of patients completing FIT or screening colonoscopy within 6 months of the mailed invitation; and (2) timely diagnostic colonoscopy, the proportion of patients completing colonoscopy within 6 months of positive FIT. Results: We mailed 14,879 invitations to 13,190 patients. Nearly half (n = 6098, 46.2%) of patients completed screening: 4,896 (80.3%) completed FIT through mailed outreach; 1,114 (18.3%) FIT through usual care; and 88 (1.4%) screening colonoscopy through usual care. Of patients with a positive FIT (n = 289), 50.5% completed diagnostic colonoscopy within 6 months, 10.7% within 6–12 months, and 4.8% after 12 months. A total of 8 cancers and 83 advanced adenomas were detected in the 191 patients completing diagnostic colonoscopy. Conclusion: After implementing and scaling up mailed outreach in a safety-net system, about half of patients completed screening, and the majority did so through mailed outreach. However, many patients failed to complete diagnostic colonoscopy after positive FIT. Results highlight the importance of adapting mailed outreach programs to local contexts and constraints of healthcare systems, in order to support efforts to improve CRC screening in underserved populations.