Title : Decomposition analysis of socioeconomic-related inequalities in vaccination dropout among children aged 12-35 months in remote and underserved settings of Ethiopia
Background: Despite increments in immunization coverage over the past decades, substantial inequality due to wealth status has persisted in Ethiopia. This study aimed to decompose the concentration index into the individual factors contributing to socioeconomic-related inequalities leading to vaccination dropout among children aged 12–35 months in remote and underserved settings in Ethiopia using a decomposition approach.
Methods: A wealth index was developed by reducing 41 variables related to the woman’s household living standards into nine factors using Principal Component Analysis. The components were further totaled into a composite score and ultimately divided into five quintiles (poorest, poorer, middle, richer, and richest). Vaccination dropout was calculated as the proportion of children who did not get Pentavalent-3 among those who received the Pentavalent-1 vaccine. The concentration curve and concentration index were used to estimate socioeconomic-related inequalities in childhood vaccination dropout. The concentration index was also decomposed to examine the contributing factors to socioeconomic inequalities in childhood vaccination dropout.
Results: The overall concentration index was -0.179 and statistically significant (p<0.01), which confirmed the concentration of vaccination dropout among the lowest wealth strata. The decomposition analyses showed that wealth index was a significant contributor to inequalities in vaccination dropout (49.73%). Place of residence also explained -16.15% of the inequality in vaccination dropout. Skilled birth attendance and availability of health facility in the kebele were also large contributors to inequality, contributing 33.64% and 12.55% to inequalities in vaccination dropout, respectively.
Conclusions: Vaccination dropout was concentrated among the lowest wealth strata. Wealth index, place of residence, skilled birth attendance, and availability of a health facility in the kebele largely contributed to this inequality. Policymakers need to address the pro-rich inequality in childhood vaccination by strengthening women’s utilization of healthcare services and accessibility of health facilities in rural kebeles.