Geographically Clustered Mailing of Fecal Immunochemical Test (FIT) Kits

Colorectal cancer (CRC) screening can save lives but is under-used, especially among minority and low-income patients in urban safety-net systems. Interventions among safety-net patients have improved screening but require additional refinement. For example, the investigators demonstrated that mailing free home fecal immunochemical tests (FIT) to urban safety-net patients doubled screening uptake (59% vs. 30%, p\<.001); however a full 41% who received FIT kits still did not complete screening. Drawing from economics, behavioral science, and healthcare delivery science, the investigators propose a spatially informed randomized intervention to further improve screening uptake. By targeting all patients in a single neighborhood at one time using waves of mailed invitations, the GeoMail intervention is designed to amplify social contagion among neighbors (i.e., positive communications and reinforcement among neighbors to complete screening) thereby increasing screening uptake. GeoMail will be live for 12 months. This intervention will not change the content of FIT kits that are already to be mailed under usual care conditions at Parkland, it will only change the timing of mailing. The aims of this study are to: Aim 1: Conduct and evaluate outcomes from a GeoMail intervention - a geographically clustered randomized trial comparing geographically clustered mailed screening invitations (treatment) to non-clustered invitations (usual care). Hypotheses (H): H1.1: Patient-level and H1.2: Neighborhood-level screening will be higher in the treatment neighborhoods, compared to usual-care neighborhoods. Aim 2: Evaluate whether patient-level or neighborhood-level indicators of patient density, race/ethnicity, and socioeconomic disadvantage moderate GeoMail impact on CRC screening. H2.1-3: All three types of factors will moderate the GeoMail intervention impact