title: The Mobile Solutions for Immunization (M-SIMU) Trial: A Protocol for a Cluster Randomized Controlled Trial That Assesses the Impact of Mobile Phone Delivered Reminders and Travel Subsidies to Improve Childhood Immunization Coverage Rates and Timeliness in Western Kenya.
abstract: BACKGROUND
  Text message (short message service, SMS) reminders and incentives are two demand-side interventions that have been shown to improve health care-seeking behaviors by targeting participant characteristics such as forgetfulness, lack of knowledge, and transport costs. Applying these interventions to routine pediatric immunizations may improve vaccination coverage and timeliness.
  
  
  OBJECTIVE
  The Mobile Solutions for Immunization (M-SIMU) trial aims to determine if text message reminders, either with or without mobile phone-based incentives, sent to infant's parents can improve immunization coverage and timeliness of routine pediatric vaccines in rural western Kenya.
  
  
  METHODS
  This is a four-arm, cluster, randomized controlled trial. Villages are randomized to one of four study arms prior to enrollment of participants. The study arms are: (1) no intervention (a general health-related text message will be texted to this group at the time of enrollment), (2) text message reminders only, (3) text message reminders and a 75 Kenyan Shilling (KES) incentive, or (4) text message reminders and a KES200 incentive. Participants assigned to study arms 2-4 will receive two text message reminders; sent 3 days before and one day before the scheduled immunization visit at 6, 10, and 14 weeks for polio and pentavalent (containing diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenza type b antigens) type b antigens) vaccines, and at 9 months for measles vaccine. Participants in incentive arms will, in addition to text message reminders as above, receive mobile phone-based incentives after each timely vaccination, where timely is defined as vaccination within 2 weeks of the scheduled date for each of the four routine expanded program immunization (EPI) vaccination visits. Mother-infant pairs will be followed to 12 months of age where the primary outcome, a fully immunized child, will be ascertained. A fully immunized child is defined as a child receiving vaccines for bacille Calmette-Guerin, three doses of pentavalent and polio, and measles by 12 months of age. General estimating equation (GEE) models that account for clustering will be employed for primary outcome analyses.
  
  
  RESULTS
  Enrollment was completed in October 2014. Twelve month follow-up visits to ascertain immunization status from the maternal and child health booklet were completed in February 2016.
  
  
  CONCLUSIONS
  This is one of the first studies to examine the effect of text message reminders on immunization coverage and timeliness in a lower income country and is the first study to assess the effect of mobile money-based incentives to improve immunization coverage.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT01878435; https://clinicaltrials.gov/ct2/show/NCT01878435 (Archived by WebCite at http://www.webcitation.org/6hQlwGYJR).
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States. dgibso28@jhu.edu.
authors.forename: Dustin G
authors.identifier: http://orcid.org/0000-0002-9073-3376
authors.initials: DG
authors.lastname: Gibson
authors.forename: E Wangeci
authors.identifier: http://orcid.org/0000-0002-4481-8889
authors.initials: EW
authors.lastname: Kagucia
authors.forename: Benard
authors.identifier: http://orcid.org/0000-0002-8591-5845
authors.initials: B
authors.lastname: Ochieng
authors.forename: Nisha
authors.identifier: http://orcid.org/0000-0003-2567-9008
authors.initials: N
authors.lastname: Hariharan
authors.forename: David
authors.identifier: http://orcid.org/0000-0002-2852-6368
authors.initials: D
authors.lastname: Obor
authors.forename: Lawrence H
authors.identifier: http://orcid.org/0000-0002-0504-3718
authors.initials: LH
authors.lastname: Moulton
authors.forename: Peter J
authors.identifier: http://orcid.org/0000-0001-8569-5507
authors.initials: PJ
authors.lastname: Winch
authors.forename: Orin S
authors.identifier: http://orcid.org/0000-0001-6756-5653
authors.initials: OS
authors.lastname: Levine
authors.forename: Frank
authors.identifier: http://orcid.org/0000-0003-3056-8425
authors.initials: F
authors.lastname: Odhiambo
authors.forename: Katherine L
authors.identifier: http://orcid.org/0000-0003-1490-3377
authors.initials: KL
authors.lastname: O'Brien
authors.forename: Daniel R
authors.identifier: http://orcid.org/0000-0001-5154-5084
authors.initials: DR
authors.lastname: Feikin
keywords: CCT; Kenya; M-PESA; SMS; conditional cash transfer; immunization; incentive; mHealth; measles; mobile; pentavalent; reminders; text message