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

Abstract

Background: Despite progress in vaccination coverage, timeliness of childhood vaccination remains a challenge in many settings. We aimed to assess if mobile phone-based reminders and incentives to health workers and caregivers could increase timely neonatal vaccination in a rural, low-resource setting.

Methods: We conducted an open-label cluster randomized controlled 1:1:1 trial with three arms in 15 communities in Northern Ghana. Communities were randomized to 1) a voice call reminder intervention; 2) a community health volunteer (CHV) intervention with incentivized rewards; 3) control. In the voice call reminder arm, a study staff member made voice calls to mothers shortly after birth to encourage vaccination and provide personalized information about available vaccination services. In the incentive arm, CHVs promoted infant vaccination and informed women with recent births about available vaccination opportunities. 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. No study activities were conducted in control communities. A population-based survey compared vaccination coverage across arms in the pre-intervention and intervention periods. The primary endpoint was completion of at least one dose of Polio vaccine within 14 days of life and BCG vaccination within 28 days of life.

Results: Six-hundred ninety births were identified; 106, 88, and 88 from pre-intervention and 150, 135, and 123 in the intervention period, in the control, voice call reminder and CHV incentive arms, respectively. In adjusted intent-to-treat analysis, voice call reminders were associated with 10.5 percentage point (95% CI: 4.0, 17.1) higher coverage of on-time vaccination, while mobile phone-based incentives were associated with 49.5 percentage point (95% CI: 26.4, 72.5) higher coverage.

Conclusion: Community-based interventions using mobile phone technologies can improve timely early vaccination coverage. A CHV approach with incentives to community workers and caregivers was a more effective strategy than voice call reminders. The impact of vaccination "nudges" via voice calls may be constrained in settings where network coverage and phone ownership are limited.

Trial registration: This trial was registered at ClinicalTrials.gov; NCT03797950.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. GEVaP study population flow.

Fig 2. Difference in coverage of timely vaccination with first Polio and BCG vaccines with GEVaP interventions, compared with control, in post-intervention initiation period (N = 408).

Difference relates to the difference in the likelihood of timely vaccination in the voice call reminder and CHV and incentives arms, compared with control arm, post-intervention initiationy. Estimates from linear regression models adjusted for baseline community-level vaccination coverage, month of birth, maternal phone ownership, network coverage, birth location, time to childbirth facility, maternal educational attainment, household electricity and TV ownership. Difference with control arm defined as β coefficient for treatment group. Variance accounts for clustering by community.

Fig 3. Change in proportion of young infants vaccinated on time pre-intervention and GEVaP intervention period, by community (N = 690).

*Timely vaccination defined as first Polio dose and BCG by 14 and 28 days of life (DOL), respectively. Estimates from linear regression models of on-time vaccination regressed on period (pre-intervention or intervention), for each community. Change over time defined as β coefficient for period, with robust variance estimates.