Replication Data for: Text Messaging Versus Postal Reminders to Improve Participation in a Colorectal Cancer Screening Program: Randomized Controlled Trial

The study aimed to assess the effectiveness of text messages as a replacement for routine postal reminders in a fecal immunochemical test (FIT) based colorectal cancer screening program in Catalonia. For that purpose, a randomized controlled trial was conducted. Study population: individuals aged 50 to 69 invited to screening who had not completed FIT within six weeks. The intervention group (n=12,167) received a text message reminder, and the control group (n=12,221) used the standard procedure (reminder letter). The primary outcome was a participation rate within 18 weeks of the invitation. The trial was discontinued, and a recovery strategy was implemented by sending a reminder letter to non-participant individuals from the intervention group. We performed a final analysis to determine the impact of the recovery strategy. Results: Interim analysis (n=7095) showed a lower participation rate among nonparticipants within six weeks in the text message group compared to the control group (16.4% vs. 20.9%, OR 0.71, 95% CI 0.63–0.81). A total of 7591 non-participants in the text message group received a second reminder by letter, reaching a participation rate of 23%. Final analysis (n=24,388) showed that the intervention group, which received two reminders, had higher participation than the control group (29.3% vs. 26.5%, OR 1.16, 95% CI 1.09–1.23). Our attempt to replace reminder letters with text messages was unsuccessful, but receiving two reminders significantly increased participation rates among non-participants within six weeks compared to one postal reminder. Additional research is essential to determine the best timing and frequency of reminders to boost participation without being intrusive in their choice of participation