The impact of short message service text messages sent as appointment reminders to patients' cell phones at outpatient clinics in São Paulo, Brazil

Int J Med Inform. 2010 Jan;79(1):65-70. doi: 10.1016/j.ijmedinf.2009.09.001. Epub 2009 Sep 26.


Objective: Nonattendance for appointments remains a challenge to health care managers and providers. The objective of this article is to present the results of a study on the impact of appointment reminders sent as short message service text messages to patients' cell phones on nonattendance rates at outpatient clinics in São Paulo, Brazil.

Design: Data were collected on scheduled appointments in four medical clinics using Clinic Manager or Clinic Web systems that can send automated messages to patients. Data on appointment attendance were collected from these systems.

Measurements: More than 29,000 appointments were scheduled between July 1, 2007, and May 31, 2008, and for 7890 of them a text message reminder was sent to the patient's cell phone. The rates of nonattendance were compared between those who were sent and those who were not sent a text message as an appointment reminder.

Results: The nonattendance reduction rates for appointments at the four outpatient clinics studied were 0.82% (p= .590), 3.55% (p= .009), 5.75% (p= .022), and 14.49% (p= < .001).

Conclusion: The study results indicate that sending appointment reminders as text messages to patients' cell phones is an effective strategy to reduce nonattendance rates. When patients attend their appointments, the facility providing care and the patients receiving uninterrupted care benefit.

Publication types

  • Comparative Study

MeSH terms

  • Ambulatory Care Facilities
  • Appointments and Schedules*
  • Brazil
  • Cell Phone / statistics & numerical data*
  • Cost-Benefit Analysis
  • Electronic Mail / economics
  • Electronic Mail / statistics & numerical data*
  • Health Care Surveys
  • Humans
  • Patient Compliance / statistics & numerical data*
  • Reminder Systems / economics
  • Reminder Systems / instrumentation*
  • Reminder Systems / statistics & numerical data*