We found no significant impact of either the Alma Sana bracelet or the Star bracelet reminders in increasing the up-to-date coverage at 12 months of age or timeliness of Pentavalent-3 or Measles-1 vaccine.
Traditional ‘wearables’ have been used as visual symbols for denoting health indicators since the last several decades. One of the first such tools was a birth control necklace which was developed in collaboration with local Ethiopian women to strengthen awareness regarding the female hormonal cycles [14]. The idea gained traction and was formalized into the ‘Couple/Cycle Bead Method’ that conveyed complex information regarding natural family planning in a simple and visually appealing way. Studies investigating the use of these beaded bracelets found them to be a simple ,low-cost, and highly acceptable family planning method [15].
Overtime, the utility of wearables for health has expanded across different disease domains and in recent years, the line between consumer health wearables and medical devices has begun to blur[16]. The upsurge of wearables is mostly concentrated in developed countries, but the concept has gained traction in low and middle-income countries as well where wearable solutions integrating data records such as tattooed bracelets for immunization [17], Near Field Communication (NFC) powered digital pendants [18] and Vaccine Indicator Reminder (VIR) bands [19, 20] are coming to the forefront.
Despite their growing influence, currently, there is limited published literature investigating the impact of these innovative tools. Our study is among the first few attempts to rigorously investigate the impact of these innovations, and our findings are corroborated by a similar study in the region which reported that a Near Field Communication (NFC) powered digital pendant worn as a necklace around the child’s neck did not have any significant impact on DTP-3 vaccination adherence [18].
The underlying appeal and utility of these simple wearables stems from one or more of the following characteristics; their ability to convey complicated information in a simple and easy to comprehend manner, serving as a visual cue and a constant reminder for undertaking the desired actions and lastly, their serving as a social signal among peers.
Our hypothesis that the bracelet would improve immunization uptake was based on the first two characteristics i.e. that the bracelet would serve as a visible and durable reminder as compared to other alternatives, and was easier to understand and interpret for uneducated caregivers.
Contrary to our findings, a study conducted in Sierra Leone using different colored silicone bracelets worn by children as a social signal that the child had completed all required vaccinations saw a 14 percentage point increase in the timely and complete vaccination coverage [21].
It is worth investigating the reasons for the null impact of our study. A key assumption of our intended theory of change was that the bracelets would be a visually evident reminder since they would be visible to the caregivers at all times compared to commonly used alternatives such as immunization cards that are not always within the caregivers’ sight [22]. However, a key finding in our study was the poor compliance of wearing the bracelet; almost half of the study participants only wore the bracelet before coming to the immunization center and only a negligible percentage of children wore the bracelet at all times, despite the study staff reiterating its importance at each follow-up visit.
As part of collecting feedback from caregivers we found out that the most commonly cited reasons for children not wearing the bracelets was their ‘inappropriate size’. Although our findings based on measuring wrist sizes of a sub-sample of children post study showed otherwise, nevertheless this serves as an important guideline to ensure that the bracelets are size-adjustable so that they could comfortably fit the wrist of the child between 0–9 months. From a longer term perspective, adherence towards wearing the bracelet also constitutes a behavioral change process which is an important mediator for the observed health outcomes. Health literature elsewhere also highlights that adherence to self-care activities including adopting or refraining from certain behaviors plays an important role in the effectiveness of health care interventions [23]. Moreover, behavior change theories grounded in psychology also emphasize the fact that making health-related behavior changes is a complex process [24] which may lead to an ‘intention-behavior’ gap [25], preventing favorable process outcomes from translating into long term behavior changes. Our findings also provide evidence of the strong reliance on the immunization card being the established immunization recall method and we may also postulate that the short duration of the study did not provide enough time to ‘institutionalize’ the use of the bracelets.
It is worth elaborating more on the favourable feedback from parents. As discussed, a majority of the caregivers in the study found the bracelet to be helpful and expressed a desire to recommend this tool to others. This corresponds to findings from other studies where caregivers in a variety of settings have expressed the need and desire for innovative and novel reminder/recall mechanisms [26] [27]. This finding is also in line with results of the study in Udaipur, India where mothers expressed increased satisfaction and acceptability for the novel digital pendant as compared to the traditional immunization reminder mechanism [18]. Our finding, therefore, serves as an important validation of the bracelets in the context of their health-oriented value. In fact, health seeking behaviour in Pakistan specifically and South Asia in general frequently features faith healers and cultural wearables such as amulets, ta’wiz, and pendants that are commonly used for protection [28], which may have led to little resistance from caregivers and facilitated the link between the bracelets and their intended health context.
We, therefore, have a strong reason to believe that our proposed intervention has potential and that certain modifications can allow it to address some of the pervasive issues with conventional reminder/recall mechanisms. Current mechanisms of reminder/recall interventions such as SMS reminders, door-to-door visits, postal reminders, telephone reminders, and community-based counselling have shown mixed results towards improving immunization coverage and timeliness which vary by settings [29]. For instance, the efficacy of SMS reminders is closely tied to the literacy levels of caregivers as well as the availability of cell phones [30], consistency of phone numbers [31] and network connectivity [13]. Similarly, door to door outreach is expensive and diverts attention away from the quality of immunization service delivery in centers. Additionally, factors such as burden on existing human resource, uncertainty about who should implement reminder services, high costs and lack of high-quality immunization records have all been cited as barriers towards the adoption of more technology dependent reminder services [32] .
Our study has certain limitations; as a result of limited time and resources, we could only follow up our study participants up till the administration of Measles 1 vaccine (recommended age 9 months) which constitutes the second last dose of the routine immunization schedule. It is difficult to predict whether we would observe a similar impact of our intervention for the Measles-2 coverage rate (recommended age 15 months) where the incidence of drop out is highest [33] [4] and retention of immunization cards is also lowest [34]. Additionally, our study only enrolled children who showed up at clinics for immunization and not those who were not vaccinating in the first place. We do acknowledge that the bracelets may have had an impact on never vaccinated children in the community due to positive externalities. However, it was beyond the scope of this study to evaluate this indirect impact and hence enrolment was only confined within the clinic setting.
Our findings also point to some critical implications for future work and for similar novel innovations targeted towards improving caregiver adherence to the routine immunization schedule. Given the widely reported positive impact of community-based educational interventions on enhancing immunization coverage [35] it is worth suggesting that any similar novel innovation or tool is accompanied by community mobilization and engagement to emphasize the importance and utility of the innovation. This is also consistent with the literature on adherence and compliance of health-related behavior whereby good communication strategies, counseling, and knowledge are important predictors of adherence [36]. Furthermore, we believe that the delivery of the bracelets through trusted vaccinators or community health workers as opposed to ‘distant’ study staff would give it more legitimacy and enable better compliance towards wearing the bracelet. This is in line with other findings where parental perceptions towards Reminder /Recall (R/R) services shows that delivery of R/R services by the government or through the established health network was preferred by the caregivers [37]. Furthermore, areas that warrant further research include: evaluating the impact of the bracelet in a purely rural community where literacy rates are much lower, introducing the bracelets even earlier on (since immunization coverage of children enrolled at BCG was higher than for those enrolled at Pentavalent-1) and considering designing bracelets for mothers to be provided at the time of antenatal care visits as studies have shown a positive association between mothers antenatal care visits and subsequent uptake of child immunizations [38, 39].