The role of place of residency in childhood immunisation coverage in Nigeria: analysis of data from three DHS rounds 2003–2013

BACKGROUND: In 2017, about 20% of the world’s children under 1 year of age with incomplete DPT vaccination lived in Nigeria. Fully-immunised child coverage (FIC), which is the percentage of children aged 12–23 months who received all doses of routine infant vaccines in their first year of life in Nigeria is low. We explored the associations between child, household, community and health system level factors and FIC, in particular focussing on urban formal and slum, and rural residence, using representative Nigeria Demographic Health Survey (NDHS) data from 2003, 2008 and 2013. METHOD: Multilevel logistic regression models were applied for quantitative analyses of NDHS 2003, 2008 and 2013 data, singly, pooled overall and stratified by rural/urban, and within urban by formal and slum. We also quantify Population Attributable Risk (PAR) of FIC. RESULTS: FIC for rural, urban formal and slum rose from 7.4, 25.6 and 24.9% respectively in 2003 to 15.8, 45.5 and 38.5% in 2013, and varied across sociodemographics. In pooled NDHS analysis, overall and stratified, final FIC adjusted odds (aOR) were: 1. Total population - delivery place (health facility vs home, aOR = 1.13, 95% CI = 0.73–1.73), maternal education (higher vs no education, aOR = 3.92, 95% CI = 1.79–8.59) and place of residence (urban vs rural, aOR = 1.69, 95% CI = 0.89–3.22). 2. Rural, urban formal and slum stratified: A.Rural – delivery place (aOR = 1.47, 95% CI = 1.12–1.94), maternal education (aOR = 4.99, 95% CI = 2.48–10.06). B.Urban formal - delivery place (aOR = 2.62, 95% CI = 1.43–4.79), maternal education level (aOR = 9.18, 95% CI = 3.05–27.64). C.Slums - delivery place (aOR = 5.39, 95% CI = 2.18–13.33), maternal education (aOR = 5.03, 95% CI = 1.52–16.65). The PAR revealed the highest percentage point increase in FIC would be achieved in all places of residence by maternal higher education: rural-38.15, urban formal-22.88 and slum 23.76, while non-attendance of antenatal care was estimated to lead to the largest reduction in FIC. CONCLUSION: Although low FIC in rural areas may be largely due to lack of health facilities and immunisation education, the intra-urban disparity is mostly unexplained, and requires further qualitative and interventional research. We show the FIC point increase that can be achieved if specific sociodemographic variable (risk) are addressed in the various communities, thus informing prioritisation of interventions.