Inequities and trends of polio immunization among children aged 12-23 months in Ethiopia: A multilevel analysis of Ethiopian Demographic and Health Survey

Introduction: Despite Ethiopia’s policy intension to provide recommended vaccination services to underprivileged populations, inequity in polio immunization persist. Objective: This study examined inequity and trends in polio immunization and determinant factors among children age 12–23 months in Ethiopia between 2000 and 2019. Methods: Cross-sectional data from 2000, 2005, 2011, 2016 and 2019 Ethiopian demographic and health surveys were analyzed with the updated version of the WHO’s Health Equity Assessment Toolkit (HEAT) software. Six standard equity measures: equity gaps, equity ratios, population attributable risk, population attributable fraction, slope index of inequality and relative index of inequality were used. Datasets were analyzed and disaggregated by the five equality stratifiers: economic status, education, place of residence, sex of the child and regions. And multilevel logistic regression analysis was used to identify determinant factors. Results: Polio immunization coverage 34.5% (2000), 44.7% (2005), 44.3% (2011), 56.4% (2016) and 60.0% (2019). Wealth index-related inequity in coverage of polio immunization between quintiles 5 and 1were greater than 20 percentage points or higher for all surveys. The population attributable risk and population attributable fraction measure in 2011 indicate that the national polio immunization coverage in that year could have been improved by nearly 36 and 81 percentage points respectively if absolute and relative wealth driven inequity, respectively, had been avoided. Coverage varied across regions; the absolute difference between Addis Ababa and Afar Region in polio immunization was 74 percentage points in 2000 and 60 percentage points in 2019. At the individual level, factors like Wealth index, maternal education antenatal care (ANC), and place of deliver were showed statistical significance. At the community level region and place of residence significantly influence equity in polio immunization. Conclusion: Although polio immunization coverage gradually increased over time, in the 20-year survey periods, inequities in coverage by wealth, educational-status, urban-rural residence and administrative regions persisted. Increasing service coverage and improving equitable access to immunizations services may narrow the existing inequity gaps.