How effective are short message service reminders at increasing clinic attendance? A meta-analysis and systematic review.

BACKGROUND AND OBJECTIVES In the last few years there has been a steady uptake of mobile phone short message service (SMS) reminders to increase medical attendance rates. We undertook a review of studies that assessed the effectiveness of SMS reminders at increasing the uptake of appointments in health care settings. METHODS We reviewed studies which involved a comparison of appointment attendance rates between patients who did and did not receive SMS reminders published prior to June 2010. We used meta-analysis methods to calculate the overall effect on attendance rates, stratified by study design and clinic type. RESULTS The review criteria were met by 18 reports, made up of eight randomized controlled trials (RCTs) and 10 controlled observational studies. Across all studies, there was significant heterogeneity in the estimated effect measure of the relationship between use of SMS reminders and clinic attendance (I(2)  = 90 percent; p < .01), so a summary effect estimate was not calculated. Stratification by study design showed that the heterogeneity was due to the observational studies. The summary effect from the RCTs was 1.48 (95% CI: 1.23-1.72) with no significant subgroup differences by clinic type (primary care clinics, hospital outpatient clinics), message timing (24, 48, and 72+ hours before the scheduled appointment), and target age group (pediatric, older). CONCLUSIONS Short message service reminders in health care settings substantially increase the likelihood of attending clinic appointments. SMS reminders appear to be a simple and efficient option for health services to use to improve service delivery, as well as resulting in health benefits for the patients who receive the reminders.