Understanding inequalities in child immunization in India: a decomposition approach

The importance of childhood immunization for healthy child growth and development is well recognized and is considered to be the best and most cost-effective lifesaver. Low socioeconomic status has been shown to be associated with low child immunization and health care utilization, but the inequalities in immunization coverage due to social and economic factors are poorly understood. This study aimed to explore the association between child immunization coverage and various socioeconomic factors and to quantify their contributions to generating inequalities in immunization coverage in India. The study data are from the National Family Health Survey-4 conducted in 2015-16. The association between socioeconomic determinants and child full immunization coverage was estimated using the χ2 test and binary logistic regression. Concentration indices were estimated to measure the magnitude of inequality, and these were further decomposed to explain the contribution of different socioeconomic factors to the total disparity in full immunization coverage. The results showed that the uptake of immunization in 2015-16 was highly associated with mother's educational status and household wealth. The concentration index decomposition revealed that inequality (immunization disadvantage) was highest among poorer economic groups and among children whose mothers were illiterate. The overall concentration index value indicates that the weaker socioeconomic groups in India are more disadvantaged in terms of immunization interventions. The results offer insight into the dynamics of the variation in immunization coverage in India and help identify vulnerable populations that should be targeted to decrease socioeconomic inequalities in the country.