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

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.

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.

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.

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.