title: SMS text message reminders to improve infant vaccination coverage in Guatemala: A pilot randomized controlled trial.
abstract: Patient reminder systems are an evidence-based way to improve childhood vaccination rates but are difficult to implement in low- and middle-income countries (LMICs). Short Message Service (SMS) texts may offer a potential low-cost solution, especially in LMICs where mobile phones are becoming more ubiquitous.
  
  
  
  To determine if an SMS-based vaccination reminder system aimed at improving completion of the infant primary immunization series is feasible and acceptable in Guatemala.
  
  
  
  A pilot randomized controlled trial was conducted at two public health clinics in Guatemala City. Infants aged 8-14 weeks presenting for the first dose of the primary immunization series were enrolled in March-April 2013. Participants randomized into the intervention received three SMS reminders one week before the second and third dose. A follow-up acceptability survey was administered to both groups.
  
  
  
  The participation rate was 86.8% (321/370); 8 did not own a cell phone and 12 could not use SMS. 96.9% of intervention parents were sent at least one SMS reminder prior to visit 2 and 96.3% prior to visit 3. Both intervention and usual care participants had high rates of vaccine and visit completion, with a non-statistically significant higher percentage of children in the intervention completing both visit 2 (95.0% vs. 90.1%, p=.12) and visit 3 (84.4% vs. 80.7%, p=.69). More intervention vs. usual care parents agreed that SMS reminders would be helpful for remembering appointments (p<.0001), agreed to being interested in receiving future SMS reminders (p<.0001), and said that they would be willing to pay for future SMS reminders (p=.01).
  
  
  
  This proof of concept evaluation showed that a new application of SMS technology is feasible to implement in a LMIC with high user satisfaction. Larger studies with modifications in the SMS system are needed to determine effectiveness (Clinical Trial Registry NCT01663636).
authors.affiliation: Department of Pediatrics, University of Colorado Anschutz Medical Campus, B065, 13123 E. 16th Ave., Aurora, CO 80045, USA; Center for Global Health, Colorado School of Public Health, Mail Stop A090, 13199 E Montview Blvd, Suite 310, Aurora, CO 80045, USA. Electronic address: Gretchen.domek@childrenscolorado.org.
authors.forename: Gretchen J
authors.initials: GJ
authors.lastname: Domek
authors.affiliation: Center for Health Studies, Universidad del Valle de Guatemala, 18 Av. 11-95, Zona 15, Vista Hermosa III, Guatemala City, Guatemala. Electronic address: Icontreras@ces.uvg.edu.gt.
authors.forename: Ingrid L
authors.initials: IL
authors.lastname: Contreras-Roldan
authors.affiliation: Department of Pediatrics, University of Colorado Anschutz Medical Campus, B065, 13123 E. 16th Ave., Aurora, CO 80045, USA; Adult and Child Center for Health Outcomes Research and Delivery Science (ACCORDS), University of Colorado Anschutz Medical Campus, Mail Stop F443, 13199 E Montview Blvd, Suite 300, Aurora, CO 80045, USA. Electronic address: Sean.o'leary@childrenscolorado.org.
authors.forename: Sean T
authors.initials: ST
authors.lastname: O'Leary
authors.affiliation: Center for Global Health, Colorado School of Public Health, Mail Stop A090, 13199 E Montview Blvd, Suite 310, Aurora, CO 80045, USA; Department of Community and Behavioral Health, Colorado School of Public Health, 13001 E 17th Place, B119, Bldg 500, Rm E3345A, Aurora, CO 80045, USA. Electronic address: Sheana.bull@ucdenver.edu.
authors.forename: Sheana
authors.initials: S
authors.lastname: Bull
authors.affiliation: Adult and Child Center for Health Outcomes Research and Delivery Science (ACCORDS), University of Colorado Anschutz Medical Campus, Mail Stop F443, 13199 E Montview Blvd, Suite 300, Aurora, CO 80045, USA. Electronic address: Anna.furniss@ucdenver.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Furniss
authors.affiliation: Department of Pediatrics, University of Colorado Anschutz Medical Campus, B065, 13123 E. 16th Ave., Aurora, CO 80045, USA; Adult and Child Center for Health Outcomes Research and Delivery Science (ACCORDS), University of Colorado Anschutz Medical Campus, Mail Stop F443, 13199 E Montview Blvd, Suite 300, Aurora, CO 80045, USA. Electronic address: Allison.kempe@childrenscolorado.org.
authors.forename: Allison
authors.initials: A
authors.lastname: Kempe
authors.affiliation: Department of Pediatrics, University of Colorado Anschutz Medical Campus, B065, 13123 E. 16th Ave., Aurora, CO 80045, USA; Center for Global Health, Colorado School of Public Health, Mail Stop A090, 13199 E Montview Blvd, Suite 310, Aurora, CO 80045, USA. Electronic address: Edwin.asturias@childrenscolorado.org.
authors.forename: Edwin J
authors.initials: EJ
authors.lastname: Asturias
mesh_terms: D000328:Adult; D001071:Appointments and Schedules; D040421:Cell Phone; D005260:Female; D006166:Guatemala; D006801:Humans; D007223:Infant; D008297:Male; D010290:Parents; D017010:Reminder Systems; D011795:Surveys and Questionnaires; D060145:Text Messaging; D014611:Vaccination; D055815:Young Adult
keywords: Childhood; Immunization; Reminder-recall; SMS; Text messaging; mHealth