The effect of SMS (text message) reminders on attendance at a community adult mental health service clinic: do SMS reminders really increase attendance?

Background Non-attendance at outpatient clinics is common and costly. Aims This study aimed to determine if sending SMS ('short message service' or text message) reminders to patients before appointments reduced non-attendance. Methods We collected outpatient data at Ballyfermot and Lucan Community Adult Mental Health Service, Dublin, Ireland during 6-month periods (a) immediately prior to the introduction of SMS reminders for outpatient appointments; (b) immediately following the introduction of SMS reminders; and (c) two and a half years later. Results In the 6-month period prior to SMS reminders, 2170 outpatient appointments were offered and there was a 22.2% non-attendance rate. In the 6-months following the introduction of SMS reminders, 2092 appointments were offered and the non-attendance rate fell to 13.9% (p < 0.001), with the lower non-attendance rate among those who did not receive SMS reminders (9.7%) rather than those who did (15.7%) (p = 0.0002). There were 98 appointment cancellations during this period (73% via SMS messaging). In the 6-month period two and a half years after the introduction of SMS reminders, 2474 appointments were offered and the non-attendance rate rose to 19.3%; this did not differ between those who received SMS reminders (19.3%) and those who did not (19.1%) (p = 0.38209) and was still lower than the rate prior to SMS reminders (p = 0.01321). During this period, 197 appointments were cancelled (75% via SMS messaging). Conclusions The chief value of SMS reminders lies not in reminding patients of appointments but in providing a convenient way to cancel them, thus allowing more appointments to be offered.