JMIR Publications

ABSTRACT

Background:

Within the worldwide challenge of tackling vaccine hesitancy, the Strategic Advisory Group of Experts on Immunization strongly promotes vaccination reminder and recall interventions which, together with the new opportunities offered by scientific progress, represent the key to successfully immunize the target population classes.

Objective:

A systematic review with meta-analysis was conducted to provide an assessment of the effectiveness on increase in vaccination coverage for different interventions compared to the standard vaccination offer.

Methods:

Two databases were consulted in February 2022, retrieving 1,850 studies. PRISMA statement guidelines were adopted and 80 manuscripts (47 trial/RCTs, and 33 before–after studies) were included after the assessment phase. Meta-analysis with random-effects model was performed by using STATA software (ver.14.1.2). The selected outcome was the relative risk (RR) of vaccination coverage improvement. Furthermore, meta-regression analyses and funnel plots were performed for the included manuscripts.

Results:

The analyses showed, for the interventions considered cumulatively, an overall efficacy of RR=1.22 (95% CI: 1.18–1.25) for RCT and RR=1.70 (95% CI:1.54–1.87) for before – after studies. Subgroup analyses allowed to identify multicomponent interventions (RR=1.48; 95% CI:1.32–1.66) and recall clinical interventions (RR=1.25; 95% CI:1.17–1.34) as the most efficacious in increasing vaccination coverage for RCTs. On the other hand, educational (RR=2.13; 95% CI:1.60–2.83) and multicomponent (RR=1.61; 95% CI:1.43–1.82) interventions achieved the highest levels of increase for before-after studies. Meta-regression analyses showed that middle-aged adult population was associated with an higher increase (RCT: coefficient 0.51, 95% CI:0.09–0.61; before–after: coefficient= 1.27; 95% CI:0.70–1.84).

Conclusions:

Community, family, and healthcare-based multidimensional interventions, as well as education-based catch-up strategies, effectively improve vaccination coverage. Therefore, their systematic implementation could be utmost relevant to target under-vaccinated population classes, thus aligning with nationally scheduled coverage levels and trying to eliminate or eradicate vaccine-preventable diseases. Clinical Trial: The review protocol was registered on PROSPERO with the number CRD42022307311 and it is available online.