Objective: To evaluate the effectiveness of cellular telephone text messaging as a reminder tool for improving adherence to sunscreen application.
Design: We conducted a randomized, controlled trial of the effect of an electronic text-message reminder system on adherence to sunscreen application. Adherence to daily sunscreen use was evaluated using a novel electronic monitoring device.
Setting: Participants were recruited from the general community.
Participants: Seventy participants constituted a volunteer sample from the general community. The inclusion criteria required participants to be 18 years or older, to own a cellular telephone with text-message features, and to know how to retrieve text messages. Intervention Half of the participants received daily text-message reminders via cellular telephone for 6 weeks, and the other half did not receive reminders. The text-message reminders consisted of 2 components: a "hook" text detailing daily local weather information and a "prompt" text reminding users to apply sunscreen. Main Outcome Measure The primary end point of the study was adherence to sunscreen application measured by the number of days participants applied sunscreen during the 6-week study period.
Results: All 70 participants completed the 6-week study. There were no statistically significant differences in baseline characteristics between the 2 study groups. At the end of the study period, the 35 participants who did not receive reminders had a mean daily adherence rate of 30.0% (95% confidence interval, 23.1%-36.9%). In comparison, the 35 participants who received daily text-message reminders had a mean daily adherence rate of 56.1% (95% confidence interval, 48.1%-64.1%) (P < .001). Among the participants in the reminder group, 24 (69%) reported that they would keep using the text-message reminders after the study, and 31 (89%) reported that they would recommend the text-message reminder system to others. Subgroup analysis did not reveal any significant demographic factors that predicted adherence.
Conclusions: Despite awareness of the benefits of sunscreen, adherence is low, even in this population, for whom adherence was knowingly monitored. Short-term data demonstrate that using existing cellular telephone text-message technology offers an innovative, low-cost, and effective method of improving adherence to sunscreen application. The use of ubiquitous communications technology, such as text messaging, may have implications for large-scale public health initiatives. Trial Registration clinicaltrials.gov Identifier: NCT00535769.