Mailing free stool test kits to patients at San Diego County community health centers kept colorectal cancer screening about 11 percentage points higher than at comparison clinics for two years, but the advantage shrank to a statistically insignificant 2.9 points in the third year, according to a randomized trial published Oct. 21, 2026, in JAMA Network Open.
The trial missed its main goal, a lasting difference at three years. The researchers said a change in how the year-three mailing was done, prompted by pandemic-related delays and limited resources, likely played a role, along with a rebound in screening at the comparison clinics.
