Director of Research Informatics University of Nebraska Medical Center Omaha, Nebraska, United States
Background: Children are under-vaccinated and thus under-protected against COVID-19. A caregiver’s decision to vaccinate their child depends on many factors. Bundling multiple strategies into a single mobile health (mHealth) application (app) may be useful to promote COVID-19 vaccine uptake for children among their caregivers. Objective: To determine the effectiveness of a caregiver-facing mHealth app on their child’s receipt of COVID-19 vaccine. Design/Methods: Caregivers of children unvaccinated for COVID-19 across 15 states and from 29 clinics in the IDeA States Pediatric Clinical Trials Network were randomized to receive either a clinic and demographic customized app with personal narratives and behavioral nudges to encourage COVID-19 vaccine uptake (VUp), or an app focused on general pediatric health (GenH). Caregivers self-reported (with record verification) their child’s COVID-19 vaccinations during the subsequent 24-week study period. Primary series completion (primary) and initiation (secondary) were the outcomes. Mixed-effect Poisson regression models with robust variance estimation were used to determine the effect of VUp. Models were run among all randomized caregivers (intention to treat [ITT] analysis) and then among only those caregivers who used the app at least once (modified ITT [mITT] analysis). Models were also stratified by age and rurality. Results: From 15Jul22-14Feb23, 722 (34% rural, 41% non-Hispanic white) caregivers of 1,202 unvaccinated children were enrolled in the study (Table 1). Among all caregivers, 464 (62%) used their assigned app at least once. Among children of VUp caregivers, 22 (3.7%) and 13 (2.2%) initiated and completed the COVID-19 vaccine series, respectively, compared to 22 (3.6%) and 7 (1.1%) of children of GenH caregivers. In ITT analyses, the unadjusted relative risk (RR) of series completion was 1.80 (95%CI: 0.72-4.49) and initiation was 0.97 (95%CI: 0.54-1.73) for VUp vs. GenH (Figure 1). Among rural children, the unadjusted RR of series completion was 6.26 (95%CI: 1.39-28.24). Adjusted ITT and both unadjusted and adjusted mITT analyses showed similar magnitudes of effects.
Conclusion(s): Customized, scalable mHealth apps may be used to try to increase COVID-19 vaccine uptake in children. Overall low vaccination uptake in this diverse cohort, which parallels the low pediatric uptake nationwide, limited the power to detect a significant effect of exposure to the mHealth app in this study. Future studies may examine the utility of an mHealth tool together with other interventions, particularly in rural populations.
