The Effectiveness of SMS Reminders on Appointment Attendance: a Meta-Analysis.

To identify the efficacy of short message service (SMS) reminders in health care appointment attendance. A systematic review was undertaken to identify studies published between 2005 and 2015 that compared the attendance rates of patients receiving SMS reminders compared to patients not receiving a reminder. Each article was examined for information regarding the study design, sample size, population demographics and intervention methods. A meta-analysis was used to calculate a pooled estimate odds ratio. Twenty-eight (28) studies were included in the review, including 13 (46 %) randomized controlled trials. The pooled odds ratio of the randomized control trials was 1.62 (1.35-1.94). Half of the studies reviewed sent the reminder within 48 h prior to the appointment time, yet no significant subgroups differences with respect to participant age, SMS timing, rate or type, setting or specialty was detectable. All studies, except one with a small sample size, demonstrated a positive OR, indicating SMS reminders were an effective means of improving appointment attendance. There was no significant difference in OR when controlling for when the SMS was sent, the frequency of the reminders or the content of the reminder. SMS appointment reminders are an effective and operative method in improving appointment attendance in a health care setting and this effectiveness has improved over the past 5 years. Further research is required to identify the optimal SMS reminder timing and frequency, specifically in relation to the length of time since the appointment.