Mobile Nudges and Financial Incentives to Improve Coverage of Timely Neonatal Vaccination in Rural Areas (GEVaP Trial): A 3-Armed Cluster Randomized Controlled Trial in Northern Ghana

"...supports existing evidence that regular outreach to encourage and support vaccination can improve immunization coverage in low-resource settings, and may be especially effective when combined with household incentives."

Timeliness of childhood vaccines remains a challenge in many settings. At the same time, access to mobile phones and mobile data network coverage is expanding rapidly. Mobile phone-based public health (mHealth) strategies have the potential: to reach difficult-to-access populations with information and messaging; to support communication, coordination, tracking, and supervision of vaccination programmes; and to improve awareness, demand for, and utilisation of vaccine services. Financial incentives have also demonstrated impact in facilitating individual behaviour change in public health programmes. This study assessed if mobile-phone-based reminders and incentives for health workers and caregivers could increase timely neonatal vaccination in rural Karaga District in Ghana's Northern Region.

The Ghana Early Vaccination Program (GEVaP) study was conducted in a region with substantially worse socioeconomic and health status than the country overall. Approximately 35% of women in the Northern Region delivered their last child in a health facility, whereas nationally 73% on average are delivered in facilities. Less than 60% of children in the region receive the first dose of the oral polio vaccine (OPV), and only 41% receive all age-appropriate vaccinations by two years of age. One major barrier to timely vaccination in the region is timely and complete birth registration.

The cluster randomised controlled trial included three arms in 15 communities:

1. A voice call reminder intervention (5 communities) - A study staff member made voice calls to mothers shortly after birth to congratulate caregivers on the birth, to highlight the importance of early vaccinations, and to provide tailored, personalised information about available vaccination services (dates, times, locations).
2. A community health volunteer (CHV) intervention with incentivised rewards (5 communities) - CHVs, most of whom had previously been trained by Ghana Health Services (GHS), promoted infant vaccination and informed women with recent births about available vaccination opportunities. CHVs took photos of the vaccination card and/or record with the date and location that each vaccination was received and then reported vaccinations to the central study personnel via a WhatsApp mobile phone application. Both CHVs and women were provided small monetary incentives for on-time early infant vaccination in this arm, delivered using mobile phone-based banking applications.
3. Control (5 communities) - No study activities were conducted.

A local research staff member provided supervision to CHVs and tracked enrollment, birth, and vaccination reporting and verification in all communities. Field visits were conducted to monitor CHV activities, to provide engagement, and to troubleshoot challenges, and frequent communication was made with CHVs via WhatsApp to encourage participation and reporting.

Interventions in both treatment arms were launched on November 1 2018; enrollment was phased out by March 31 2019, and follow-up with enrolled particpants was completed April 30 2019. The primary outcome of interest was the likelihood of young infants receiving both the first dose of the OPV and the Bacillus Calmette-Guérin (BCG) vaccine on time.

In intent-to-treat analysis adjusting for baseline differences in vaccination coverage and other covariates, the proportion of infants in the voice call reminder arm who were vaccinated on time with the first dose of OPV and BCG during the intervention period was larger than in the control arm [adjusted difference in proportion (10.5 percentage point difference (95% confidence interval (CI): 4.0, 17.1). The proportion of infants vaccinated on time in the CHV and incentives arm during the intervention period was 49.5 percentage points larger than in the control arm (95% CI: 26.4, 72.5). Timely OPV coverage was 48.8 percentage points (95% CI: 24.5, 73.1) higher in the CHV and incentives than in the control arm. The magnitude of the absolute change in the proportion of infants vaccinated on time from pre-intervention to intervention period differed across communities, but CHV and incentive communities tended to have the largest and most consistent increases in coverage proportions over time.

Thus, this study found that "timeliness of early vaccinations in rural communities can be improved through mobile phone-based interventions delivered in the community, and are particularly effective when local CHVs implement the program and they and caregivers receive small financial incentives."

Reflecting on the findings, the researchers note that the smaller impact of the voice call reminder approach may be partially explained by the fact that only 42% of the eligible population was reached with the intervention due to poor mobile network coverage and challenges in reaching women who didn't have personal phones. "Phone reminder interventions may be more effective in settings where mobile network coverage is more reliable and phone ownership more common. Approaches that rely on SMS [short messaging service] or automated messaging for communicating with women and community health workers would be infeasible in similar settings due to limited literacy."

This intervention focused on increasing demand for vaccination among caregivers, but, as the researchers stress, timely vaccination also requires that vaccines are available and accessible. Participants reported system-level bottlenecks to access that must also be addressed for demand-side interventions to have impact.

Furthermore: "Supervision systems and appropriate remuneration for CHVs will be essential to maintain impact in similar programs. To be effective, the incentive must be large enough to initiate behavior-change, motivate action and offset any perceived costs or barriers, for both the CHVs and the caregivers. Thus policy-makers must consider the cost of not only the incentives, but of developing and maintaining a support and supervision structure that will encourage ongoing engagement and performance."

The approach used in this trial could perhaps be considered in other settings, as it engaged local community members previously trained in health promotion to undertake "activities to increase demand for and utilization of vaccination services that were already available and to help connect potential clients with available services. The intervention approach was widely acceptable to community members and caregivers, and required limited financial resources or health system infrastructure."