Interventions to increase colorectal cancer screening adherence in low-income settings within the United States: A systematic review and meta-analysis

The USPS Task Force recommends screening for colorectal cancer (CRC) in adults aged 45-75. Screening rates are low in underserved populations. We conducted a systematic review of interventions to increase CRC screening adherence in low-income settings in US. We included randomized control trials of CRC screening in-terventions conducted in low-income settings in the US. Outcome was CRC screening adherence. Random-effects meta-analysis of relative risks was conducted for the effectiveness of CRC screening interventions. We identified 46 studies that met inclusion criteria. Interventions were grouped into four categories: mailed outreach, patient navigation, patient education, and types of reminders. Mailed outreach with enclosed fecal immunohisto-chemical test (FIT) (RR 2.20, 95% CI 1.74, 2.78), guaiac based fecal occult blood test (gFOBT) (RR 4.34, 95% CI 1.29, 14.67), and without FIT/gFOBT (RR 1.80, 95% CI 1.15, 2.82) all significantly increased CRC screening, as did non-individualized education (RR 1.44, 95% CI 1.07, 1.94) and patient navigation (RR 1.62, 95% CI 1.29, 2.02). Mailed outreach with an incentive (RR 0.97, 95% CI 0.81, 1.16) and individualized education (RR 1.07, 95% CI 0.83, 1.38) did not significantly improve screening adherence. Telephone reminders are slightly more effective than reminder letters (RR 1.16, 95% CI 1.02, 1.33), but there is no difference between personal or automated phone calls (RR 1.17, 95% CI 0.74, 1.84). Mailed outreach and patient navigation are the most effective strategies to improve colorectal cancer screening in low-income populations. There was significant heterogeneity between studies, likely due to differences in intervention design, screening tests, and follow-up.