Inequities in Childhood Vaccination Coverage in Zhejiang, Province: Evidence from a Decomposition Analysis on Two-Round Surveys

Abstract

Objective: The objectives of this study were to determine the degree and risk factors of the inequity in the childhood coverage of full primary immunization (FPI) in Zhejiang province. Method: We used data from two rounds of vaccination coverage surveys among children aged 24⁻35 months conducted in 2014 and 2017, respectively. The household income per month was used as an index of socioeconomic status for the inequality analysis. The concentration index (CI) was used to quantify the degree of inequality, and the decomposition approach was applied to quantify the contributions from demographic factors to inequality in the coverage of FPI. Results: The coverage rates of FPI were 80.6%, with a CI value of 0.12028 for the 2014 survey, while the coverage rates of FPI were 85.2%, with a CI value of 0.10129 for the 2017 survey. The results of decomposition analysis suggested that 68.2% and 67.1% of the socioeconomic inequality in the coverage of FPI could be explained by the mother's education level for the 2014 and 2017 survey, respectively. Other risk factors including birth order, ethnic group, mother's age, maternal employment status, residence, immigration status, GDP per-capita, and the percentage of the total health spending allocated to public health could also explain this inequality. Conclusion: The socioeconomic inequity in the coverage of FPI still remained, although this gap was reduced between 2014 and 2017. Policy recommendations for health interventions on reducing the inequality in the coverage of FPI should be focused on eliminating poverty and women's illiteracy.

Keywords: concentration index; coverage; decomposition; inequality; vaccination.

Figure 1

The distribution of coverage of the individual vaccine and FPI by socioeconomic status in the 2014 and 2017 coverage surveys (Notes: HBV3 means the 3rd dose of the hepatitis B vaccine (HBV); PV3 means the 3rd dose of the polio vaccine (PV); DTP3 means the 3rd dose of the diphtheria-tetanus-pertussis combined vaccine (DTP); MCV1 means the 1st dose of the measles-containing vaccine (MCV); JEV1 means the 1st dose of the Japanese encephalitis vaccine (JEV)).

Figure 2

The concentration curve of inequality in the coverage of FPI in the 2014 and 2017 coverage surveys.