Collecting patient-reported follow-up data for prospective studies in the emergency department (ED) is challenging in this minimal continuity setting. The objective of this study was to determine whether text messaging study participants involved in an ongoing randomized trial resulted in a lower rate of attrition as compared to conventional telephone follow-up.

This was a nested cohort analysis of research participants enrolled in a randomized controlled trial assessing head injury discharge instructions. During the first 4 months of study follow-up, participants were contacted by a conventional telephone call. For the final 3 months, participants were contacted by text messaging following the first failed telephone attempt.

A total of 118 patients were enrolled in the study (78 underwent conventional follow-up, and 40 received text messages). During the period of conventional follow-up, 3 participants withdrew from the study. Of the remaining 75 participants, 24 (32.0%) at 2 weeks and 32 (42.7%) at 4 weeks were unable to be contacted. Of the 40 participants receiving a reminder text message, 4 (10.0%) at 2 weeks and 10 (25.0%) at 4 weeks were unable to be contacted. Overall, text messaging study participants decreased attrition by 22% (95% CI: 5.9%, 34.7%) and 17.7% (95% CI: -0.8%, 33.3%) at 2- and 4-week follow-ups, respectively.

In this ED cohort participating in a randomized trial, text message reminders of upcoming telephone follow-up interviews decreased the rate of attrition. Text messaging is a viable, low-cost communication strategy that can improve follow-up participation in prospective research studies.