Determinants of European parents' decision on the vaccination of their children against measles, mumps and rubella: A systematic review and meta-analysis

Low measles, mumps and rubella (MMR) immunization levels in European children highlight the importance of identifying determinants of parental vaccine uptake to implement policies for increasing vaccine compliance. The aim of this paper is to identify the main factors associated with partial and full MMR vaccination uptake in European parents, and combine the different studies to obtain overall quantitative measures. This activity is included within the ESCULAPIO project, funded by the Italian Ministry of Health. ORs and CIs were extracted, sources of heterogeneity explored and publication bias assessed. Forty-five papers were retrieved for the qualitative study, 26 of which were included in the meta-analysis. The following factors were associated with lower MMR vaccine uptake: misleading knowledge, beliefs and perceptions on vaccines (OR 0.57, CI 0.37-0.87); negative attitudes and behaviors toward vaccination (OR 0.71, CI 0.52-0.98); demographic characteristics, such as different ethnicity in Southern populations (OR 0.44, CI 0.31-0.61), higher child's age (OR 0.80, CI 0.76-0.85); low socio-economic status (OR 0.64, CI 0.51-0.80), especially low income (OR 0.39, CI 0.25-0.60) and education (OR 0.64, CI 0.48-0.84), high number of children (OR 0.54, CI 0.42-0.69), irregular marital status (OR 0.80, CI 0.66-0.96). The factors explaining heterogeneity were country location, administration modality, collection setting and responses reported on MMR alone or in combination. Findings from this study suggest policy makers to focus communication strategies on providing better knowledge, correct beliefs and perceptions on vaccines, and improving attitudes and behaviors in parents; and to target policies to people of ethnic minority from Southern Europe, low educated and deprived, with higher number of children and non-married marital status.