The effect of mailed outreach on FIT completion among patients aged 45-50 in a safety net healthcare system.

Purpose: Colorectal cancer screening is recommended starting at age 45, but there has been little research on strategies to promote screening in patients younger than 50.

Methods: An outreach program quasi-randomly assigned patients aged 45-50 without recent fecal immunochemical test (FIT), colonoscopy or contraindications to screening to two intervention arms: electronic outreach with email and text (electronic outreach only) versus electronic outreach plus mailed outreach with FIT, an instructional letter and a prepaid return envelope (mailed + electronic outreach). In response to known disparities in screening uptake, all Black patients were assigned to receive mailed + electronic outreach.

Results: Among patients quasi-randomly assigned to an intervention (non-Black patients), the 180-day FIT completion rate was 18.8% in the electronic outreach only group (n = 1,318) and 25.0% in the mailed + electronic outreach group (n = 1,364) (difference 6.2% [95% CI 3.0, 9.4]). FIT completion was 16.6% among Black patients (n = 469), 8.4% (95% CI 4.1, 12.6) lower than among non-Black patients also assigned to mailed + electronic outreach.

Conclusion: Among patients aged 45-50, mailed + electronic outreach had a greater effect on FIT completion than electronic outreach alone. Crossover between intervention groups likely lead to an underestimation of the effect of mailed outreach.