Can wireless text messaging improve adherence to preventive activities? Results of a randomised controlled trial

Objective: To determine the effectiveness of cell phone wireless text messaging for improving adherence to a healthy behaviour. Design: A randomised, unblinded, controlled trial was conducted with 102 subjects, 18 years or older, each having a cell phone and willing to take 1 vitamin C pill per day for 1 month for preventive reasons. Intervention group participants received text messaging reminders and were asked to acknowledge receiving their messages after taking the vitamins, whereas control group subjects had no text messaging activity. Measurements: Self-reported adherence and the, number of participant text messages acknowledging vitamins taken. Results: Both groups reported an increased adherence after the trial: by 246% for the intervention group and by 131% for the control group. There was a non-significant difference between the two groups at endpoint: an average difference of 0.8 between the number of pills missed in the last week of the trial (2.5 out of 7 in the intervention and 3.3 out of 7 in the control group) with a power of 0.54. The study revealed a significant correlation (coefficient= -0.352, sig. = 0.01) between the average number of text messaging acknowledgements sent by the intervention group participants and the number of pills they reported missed during the last week of the trial. Conclusion: This was a small randomised controlled trial with inconclusive but encouraging results. It suggests a new approach in addressing insufficient adherence in outpatient conditions and shows that the use of information technology tools for compliance warrants further research. (c) 2008 Elsevier Ireland Ltd. All rights reserved.