Regional variations of childhood immunisations in Senegal: a multilevel analysis

Objectives To estimate geographical variations of child immunisation at the regional level in Senegal, to identify individual and contextual factors that could explain these regional discrepancies, and to measure their effects. Methods Data come from the 2015, 2016 and 2017 Senegalese Demographic and Health Survey, a national survey targeting women aged 15-49, with a questionnaire focusing on health and reproductive issues including their children's immunisation status. We restricted the analysis to children aged 12-23 months (n = 4955) and conducted a multilevel logistic regression to assess individual and contextual factors associated with complete immunisation coverage. Results The complete immunisation coverage rate of children was estimated at 68% and ranged from 41% in the region of Kedougou to 83% in the region of Dakar. The inter-regional variance was significantly different from zero (P = 0.006) in the empty multilevel model. It decreased by more than half (57 %) after adjusting for individual factors but remained significantly different from zero (P = 0.010). Regional variations of complete immunisation rates drastically decreased and were no longer statistically significant (P = 0.343) after adjusting for the following regional factors: population density, density of hospitals, literacy rate and proportion of health facilities with an antenatal care service. Conclusions Regarding health policies designed to improve childhood immunisation and to reduce related inequalities, our results highlight the need to take into account both individual and contextual factors, with a focus on rural and deprived areas where children are at higher risk of incomplete immunisation.