Multilevel and geographically weighted regression analysis of factors associated with full immunization among children aged 12-23 months in Ethiopia.

Immunization is the process of building immunity or resistance to an infectious disease, typically through administering a vaccine. It is one of the most effective strategies for lowering child morbidity and death. It protects against more than 20 potentially fatal diseases, increasing longevity and health. Despite progress, Ethiopia failed to meet its vaccination coverage target. The magnitude of full immunization is different across areas. Therefore, conducting geographically weighted regression to identify the local factors and multilevel analysis to investigate and identify factors associated with full immunization coverage among children aged 12-23 months is necessary. The study was conducted using the 2019 Ethiopian Mini Demographic Health Survey dataset. A sample of 1028 weighted children aged 12-23 months were included in the analysis. Descriptive statistics were used to describe variables. For the spatial analysis, Arc-GIS version 10.8 statistical software was used. Spatial regression (geographically weighted regression) was done to identify factors associated with the proportion of full immunization, and model comparison was based on adjusted R2 and Akaike Information Criteria (AICc). Multilevel mixed-effect binary logistic regression models were fitted to identify factors associated with full immunization. The fitted models were compared based on log-likelihood, deviance, median odds ratio, and Proportional Change in Variance. Finally, statistically significant factors were reported using an adjusted odd ratio (AOR) with a 95% Confidence Interval for fixed effect. All variables with a p-value less than 0.05 in the final model were considered statistically significant factors. In Ethiopia, the overall full immunization coverage among children aged 12-23 months was 40.58%, with spatial variation across regions in Ethiopia. The significant spatial distribution of full immunization coverage among children aged 12-23 months was detected in northern Tigray, Addis Ababa, central Oromia, and southeastern Amhara regions. The proportion of rural residents,the proportion of women aged 35-44 years,  the proportion of women who had ANC 4 and above andthe proportion of women who had PNC were local factors associated with the proportion of full immunization among children aged 12-23 months. Rural residence [AOR 0.27 (95% CI 0.10, 0.70)], family size 4 and above[AOR 0.41 (95% CI 0.17, 0.96)], never breastfeed [AOR 0.026(95% CI 0.003, 0.21)], 1-3 times ANC visit [AOR 0.45 (95% CI 0.23, 0.86)], being from Oromia region [AOR 0.23 (95% CI 0.05, 0.97)], Eastern pastoralist region [AOR 0.09 (95% CI 0.023, 0.35)], age 35-44 years [(AOR 6 (95% CI 1.57, 22.9)], and PNC [AOR 2.40 (95% CI 1.24, 4.8)] were significant factors associated with fully immunization in multilevel mixed effect analysis. Full immunization coverage in Ethiopia is below the global target with significant geographical variation. The high proportion of rural residents, the high proportion of women who had ANC 4 and above, mothers who had a high proportion of PNC, and the high proportion women age 35-44 years were local geographical factors for the proportion of full immunization among children age 12-23 months in Ethiopia. Women who had PNC, ANC visits four or more times, and increased maternal age were positively associated, whereas larger family size, no breastfeeding, rural residence, and being from Oromia and eastern pastoralist region were negatively associated with full immunization. Strengthening maternal and child health services, focusing on rural areas and low-coverage regions, is essential to increase immunization coverage in Ethiopia.

Do inequalities exist in the disadvantaged populations? Levels and trends of full and on-time vaccination coverage in two Nairobi urban informal settlements.

There has been an improvement in childhood vaccination coverage over the last two decades worldwide. However, inequities exist among different populations. Vaccination programs should focus not only on increasing coverage but as also in timeliness to ensure maximum protection. This study examined the levels, inequities, and trends of full and on-time vaccination coverage in two urban informal settlements in Nairobi. The study used longitudinal data from the Nairobi Urban Health and Demographic Surveillance System from 2003 to 2017 to estimate full and on-time vaccination coverage and assess inequalities by background characteristics. The frailty shared Cox model was used to assess time to full- and on-time- immunization coverage. Out of 32,018 children aged 12 to 59 months, less than half (46.7%) produced a vaccination card during the interview. Full and timely immunization coverage was higher in Viwandani site, among Kikuyu and Kamba ethnic groups, and children from the richest quintile. Timely vaccination was below 50% throughout the survey periods. After accounting for the intragroup correlations, for a given level of frailty, the hazard for being fully immunized was 10% more likely among the wealthiest compared to the poorest children. The hazard for being fully immunized was 16%, 16% to 19% less likely for Luhya, Luo, and others as compared to the Kikuyu ethnicity respectively. In conclusion, the study has shown that coverage has been increasing over the years but inequalities exist in immunization coverage among the most disadvantaged populations. More focused intervention approaches that target the disadvantaged groups are needed.