Enhancing Health Care Access With Cellular Technology: Networked and Mobile Technologies to Improve Uptake and Coverage of Vaccinations
Phase: NA
Conditions: Vaccination
Sponsor: Johns Hopkins University

 
 
 
 
 
 
Study Title: Enhancing Health Care Access with Cellular Technology 
 
NCT Number: NCT03180138 
 
PI: Sanjay Kumar Jain 
 
Date: December 15, 2016    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study design and participants 
We prospectively enrolled children 24 months and younger and pregnant women from a rural community in the 
Mewat region located within the state of Haryana, India from July 11, 2016 to July 20, 2017. Recruitment and 
follow up were performed concurrently, though the recruitment target was met on February 11, 2017. The study was 
administered by Bal Umang Drishya Sanstha (BUDS), a New Delhi based non-profit organization with a focus on 
child health. This study was approved by the Research Ethics Committees of BUDS, New Delhi, India and the Johns 
Hopkins University, Baltimore, MD, USA. This trial is registered with ClinicalTrials.gov, number NCT03180138. 
 
Study Procedures 
An encrypted, cloud-based software platform developed by Royal Datamatics Pvt Ltd (RDPL), New Delhi, India 
was used for record keeping and delivery of automated mobile-phone reminders and compliance-linked incentives 
(Supplementary Figure 1). Any child 24 months or younger at the time of enrollment, with a mobile-phone in the 
household and the ability of their caregiver to provide written informed consent were considered eligible for this 
study. After obtaining written informed consent from the caregiver, basic demographic information, Global 
Positioning System (GPS)-location and caregiver’s finger biometrics were collected. While the standard of care in 
this setting involves the use of written immunization records (cards and records at the local primary health center) 
and verbal notification of follow up visits, record keeping for all groups in this study, including the control group, 
was performed using the software platform. Eligible subjects were randomly assigned to one of three study groups: 
self-returns with software platform for record keeping (control), automated mobile-phone reminders alone, and 
automated reminders with compliance-linked incentives in the form of mobile-phone talk-time. At the time of 
enrollment, data on prior immunizations received by the child were obtained from government-issued immunization 
cards provided by the families. If cards were unavailable or lost, immunization records were verified using written 
records at the local primary health center. The government-run National Immunization program (Supplementary 
Table 1) provided and administered the immunizations. The date for the next scheduled immunization visit was 
provided at each follow up by the government staff and entered into the software platform by the field workers. 
Each follow up visit was also correlated with the scheduled return date (if recorded in the system) of the 
administered immunization. Since finger identification is unreliable in young children,13, 14 the child’s name along 
with their caregiver’s fingerprint was used to ensure positive identification of individual children at every visit. The 
GPS coordinates (longitude and latitude) were also recorded at recruitment and at each follow up visit. All users 
(field staff and study team) were identified and logged onto the software platform using biometric identification. For 
the study groups receiving automated reminders, Short Message Service (SMS) in the local language (Hindi) were 
sent. At follow up visits, mobile-phone minutes equivalent to INR 30 (~USD 0·5) per completed immunization were 
provided in the compliance-linked incentives group. The amount of incentive was determined after input from the 
local investigators as well as the community workers. All data transfers and compliance-linked incentives 
transactions were automated and occurred in real-time.  
 
Randomization and masking 
Randomization was stratified by group (young children or pregnant) using a block randomization algorithm (block 
size of six), but in the current manuscript, only data for children is presented. All caregivers were informed of their 
child’s group assignment and study field staff had access to group assignments for individual patients at the time of 
recruitment or follow up visits; however, all other study team members were blinded to the group assignments until 
the end of the study and after analysis of the blinded groups.  
 
End Points 
Immunization coverage was the primary outcome of the study and was calculated for each child as the proportion of 
the total number of immunizations received divided by the total number of immunizations required at the time of 
measurement (i.e. at enrollment, end of study, etc.). We also calculated the cost in mobile-phone messaging and 
compliance-linked incentives. Timeliness of immunizations was a secondary outcome measure and was defined as 
the proportion of immunizations administered before or within 14 days after the scheduled date recorded during the 
study. 
 
 
 

Authentication and follow up: The field staff were locally recruited and trained prior to the study. A pilot run of the 
software platform was performed at the study site in May-June 2016 to assess web and mobile-phone connectivity 
and to ensure that all operations performed optimally in real-time. At the start of the study, each mobile-phone was 
authenticated by a two-step process using an automated Short Message Service (SMS) verification code sent to the 
caregiver’s mobile-phone during enrollment. The authenticated mobile-phone would receive a welcome message 
which was verified by the field worker. For the group receiving compliance-linked incentives, an additional 
authenticated step was utilized to ensure that mobile-phone on different carriers could receive automated incentives. 
The field worker identified the carrier by inspecting the mobile-phone screen or the SIM card and entering this 
information into the software platform. This immediately triggered delivery of mobile-phone talk-time equivalent to 
Indian Rupee (INR) 20 (~USD 0·33) to the caregiver’s mobile-phone, which was then manually verified by the field 
worker. INR 30 (~USD 0.50) per completed immunization was provided subsequently to this group. Pre-scripted 
instructions were verbally provided at recruitment and at each follow up visit as follows: caregivers of children 
assigned to the control group were informed to come back for immunization at the next scheduled date, caregivers of 
children assigned to automated mobile-phone  reminders alone were informed to come back for immunization on the 
date indicated by the automated mobile-phone reminder and caregivers of children assigned to automated reminders 
with compliance-linked incentives were informed to come back for immunization on the date indicated by the 
automated mobile-phone  reminder, and that they would receive a specified amount of mobile-phone  talk-time at 
the follow up visit.  
 
Biometric identification: Biometric information (right index finger print) for the caregiver was collected at 
enrollment and verified by scanning the same finger seven times. In rare cases where the right index finger was not 
reliable, the right thumb, left index finger or left thumb was used in that order. Additional caregivers could be added 
during follow up visits and mobile numbers for caregivers could also be updated, but these procedures required the 
same verification process as described earlier. 
 
Automated reminders and compliance-linked incentives: For the study groups receiving automated reminders, SMS 
messages in the local language (Hindi) comprising the name of the child and the return date for the next scheduled 
immunization visit were sent. For the group receiving compliance-linked incentives an SMS message in Hindi 
stating that mobile-phone talk-time [in Indian Rupee (INR)] would be received on successful completion of the 
scheduled visit was sent simultaneously with the automated reminder. SMS messages were sent at 8:00 AM Indian 
Standard Time two days before and on the scheduled day of the immunization and messages were no longer than 
two sentences. For children who did not return on or before the scheduled date, two additional automated SMS 
reminders were sent the day after and seven days after the scheduled return date. At follow up visits, mobile-phone 
minutes equivalent to INR 30 (~USD 0·5) per completed immunization were provided in the compliance-linked 
incentives group. Immunizations received by a subject elsewhere during the study could also be added to the 
immunization records for both study groups and the control group, but compliance-linked incentives were only 
provided for immunizations registered by the software platform in the appropriate study group. Automated 
reminders were sent to all verified caregivers for a given child, but compliance-linked incentives were only provided 
to the primary caregiver’s mobile-phone (identified during enrollment). All data transfers and compliance-linked 
incentives transactions were automated and occurred in real-time. We also calculated the cost in mobile-phone 
messaging and compliance-linked incentives. Since automated reminders were sent to multiple verified caregivers 
for each child, the costs for mobile-phone messaging (USD 0·0048 per message) was a cumulative of all messages 
send to all caregivers. However, compliance-linked incentives were only provided to the primary caregiver’s 
mobile-phone and these costs were also included. 
 
 
 
 
 
Statistical Analysis Plan 
 
Sample size: Prior to the study, we anticipated that our best intervention would increase the baseline 
immunization coverage by least 20% compared to the control group. Assuming up to a 20% exclusion rate, we 
calculated that a sample of size 175 per group would yield us 90% power at 5% level of significance for this 
outcome. 

 
Statistical analysis: Baseline data across the three study groups was summarized using either median and inter‐
quartile range (IQR) or frequencies and percentages. Multivariable Poisson regression analysis was used to 
estimate adjusted immunization rates in the two test study groups with the control group as reference. To 
compare immunization coverage at enrollment and at the end of the study, the incidence rate ratio was calculated 
accounting for median patient days in the study and the number of subjects for each intervention group. 
Unadjusted immunization coverage for each study group was calculated with Poisson exact 95% confidence 
intervals. Multivariable Poisson regression analysis was used to estimate adjusted immunization rates in the two 
test study groups with the control group as reference. Comparison between groups for timeliness of immunization 
was calculated using the Fisher‐exact test. Data analysis was performed using Stata Version 14 (StataCorp LLC, 
College Station, TX USA) or GraphPad Prism Version 6∙05 (La Jolla, CA 92037 USA).