University of Cambridge (Oliver-Williams, Brown, Devereux, Fairhead, Holeman); University College London (Brown, Fairhead); University of Edinburgh (Holeman); Medic Mobile (Holeman)
"There is reason to be optimistic regarding the potential for mobile phones to increase vaccination coverage in LMIC."
The aim of this study was to conduct a systematic review of the available literature on the use of mobile health (mHealth) to improve vaccination in low- and middle-income countries (LMIC) with large numbers of unvaccinated children. It was motivated by the observation that top-down communication strategies have been found to be detrimental to some vaccination drives in LMIC, whereas interpersonal communication incorporating local leaders and networks and utilising a wide range of communication channels are more successful. Given that nearly 100% of the world's population lives within reach of a mobile phone signal and that mobile technology is widely used to improve health communication, mHealth interventions might be used to increase coverage. This is an issue considering that an estimated 18.7 million infants worldwide did not receive routine vaccinations such as the DPT3 (diphtheria) vaccine in 2014, and over 60% of these children live in just 10 LMIC.
In February 2017, MEDLINE, Scopus, and Web of Science, as well as three health organisation websites - The Communication Initiative, TechNet-21, and PATH - were searched to identify mHealth intervention studies on vaccination uptake in 21 countries. Ten peer-reviewed studies and 11 studies from white or gray literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe, and Kenya. Of the 21 studies fulfilling the inclusion or exclusion criteria, 10 were peer-reviewed, of which 3 were randomised control trials (RCTs). Thus, it is a limitation that the included studies were predominantly observational studies that appraised process and usage output.
In total, 10 peer-reviewed studies and 7 white or gray studies demonstrated improved vaccination uptake after interventions ranging from SMS (short message service, or text) messages sent to families to remind and encourage them to take their children to the health centre for vaccinations, to using mobile phones to record which settlements have been covered by vaccination campaigns, to mobile phone apps helping health workers to update and access relevant data to facilitate vaccination campaigns. Here are a few selected examples of findings:
- Eight peer-reviewed studies reported the use of phone calls or SMS reminders for vaccinations, two of which additionally offered cash incentives. The three studies that did not offer cash incentives included an RCT by Bangure et al conducted in Zimbabwe. SMS reminders were sent to parents (n=152) when their baby was 6, 10, and 14 weeks old, in addition to routine health education. The control group received health education alone (n=152). At all three time points, the percentage of children fully vaccinated with the relevant dose of polio, pentavalent, and pneumococcal vaccines was significantly higher in the intervention than the control group (<.001), and the delay in receiving the vaccinations was significantly less in the intervention than the control group (<.001).
- Three studies used mobile-based interactive learning apps to aid or track the progress of health workers in vaccination. For example, Touray et al utilised the global positioning system of Android phones to track where vaccination teams during polio campaigns had been, which helped reduce the number of settlements in northern Nigeria that were not covered in the last 3 campaigns - from 5,833 in 2014 to 1,257 in 2015.
- Another successful strategy included the involvement of India's national telecom authority, who replaced the dial tone on mobile phones with a recorded message that reminded the public of National Immunization Day. The Mobilink mobile operator in Pakistan recorded 13,000 SMS messages about unvaccinated children during the annual polio vaccination campaign in 2010 and circulated 7 million SMS reminders in 2009.
- A decrease in the percentage of unvaccinated children and an increase in the number of children with a vaccination card were found when health care workers used their mobile phones to play a prerecorded message to families.
- A 41% increase in vaccination rates was observed in rural India after the introduction of an integrated mobile channel providing health information and connecting mothers with health services.
Overall, the literature reviewed indicates that mobile technology can be used in a variety of ways to improve vaccination uptake. Although most studies lacked comparison groups, the results broadly suggest an improved uptake of vaccinations with mobile phone-based interventions. However, some studies reported no improvement upon intervention. A study from Pakistan found low response rates to SMS messages about vaccinations, even when a financial reward was attached. Furthermore, the studies that were reviewed, as well as the related research that these studies cited to explain the design of their interventions, raise a number of challenges that can impede the integration of mobile phones into vaccination programmes. For instance, in LMIC, generally, women are 21% less likely to own a mobile phone than men (increasing to 37% in Asia). As women are the primary caregivers to children, this may impact mHealth vaccination interventions. Furthermore, two-thirds of illiterate adults are women, which can further reduce the effectiveness of SMS messages. In households where the father owns the mobile phone, it is imperative that the father is engaged in the project.
Other considerations include the fact that frequent exposure to SMS messages can result in the effectiveness of the message being weakened. Therefore, the effectiveness of messages of different length and over time needs to be assessed when sending SMSs. Also important: developing the appropriate infrastructure and ensuring adequate resources are available (mHealth can improve access to vaccines only as long as they remain consistently available). In addition, increasing demand for vaccination can have unintended consequences. One study reported that extensive and comprehensive communication campaigns for 15 new vaccines led to greater demand for vaccination in a number of LMIC. However, high demand resulted in vaccine shortages, which later thwarted the increased demand. For this reason, policymakers and implementers of mHealth interventions to improve vaccination programmes are advised to be aware that mHealth interventions are deeply complex and context-dependent.
As outlined in the paper's conclusion, there is preliminary evidence to support the use of mHealth technology to increase vaccination coverage in LMIC. At the same time, there are gaps, such as the fact that relatively more compelling evidence exists for mHealth interventions addressing demand-side barriers to service uptake, whereas fewer evaluated interventions aim to boost immunisation by strengthening health systems through data management, decision support, or provider training and education. Further research is needed to determine the most effective mHealth interventions and to refine their use - for example, clarifying the optimal schedule of reminders for programmes using SMS reminders of vaccination appointments. It will also be necessary to evaluate different mHealth interventions against each other, and against other potential programmes, to examine their comparative cost-effectiveness at increasing vaccination coverage.
JMIR Mhealth Uhealth 2017;5(10):e148 DOI: 10.2196/mhealth.7792 PMID: 28978495. Image credit: Ken Banks, image courtesy of kiwanja.net