Economic-related inequalities in hepatitis B virus infection among 115.8 million pregnant women in China from 2013 to 2020

Background: Hepatitis B virus (HBV) infection is a serious global health problem and China has the largest disease burden. Literatures focusing on economic-related inequalities in HBV infection among pregnant women are scarce. We aimed to quantify the economic-related inequalities and the change over time in HBV infection among pregnant women in mainland China from 2013 to 2020 to inform strategies considering economic-related inequalities. Methods: We used national cross-sectional secondary data of pregnant women in 30 provinces from the National Integrated Prevention of Mother-to-Child Transmission of HIV, Syphilis and Hepatitis B Programme (iPMTCT Programme) from 2013 to 2020. We calculated concentration index and adjusted difference between the rich and the poor in the multivariable generalized estimating equation (GEE) model to measure economic-related inequality, after adjusted other risk factors. Findings: In this study, a total of 115,789,148 pregnant women of mainland China from 2013 to 2020 were included, the overall hepatitis B surface antigen (HBsAg) prevalence was 6.27% (95%CI: 6.26%-6.28%). The curve lay above the equality line, with the negative value of the concentration index of -0.027, which indicated that economic-related health disparities exist in the distribution of HBV infection and the inequality disadvantageous to the poor (pro-poor). The concentration index showed a trend of fluctuating decline, indicating that economic-related inequalities in HBsAg prevalence were narrowing. The adjust difference between counties with lowest economic level and counties with highest economic level (reference group) were 46.3% in HBsAg prevalence (all p<0.05) in the multivariable GEE model, after controlling other confounders. A significant dose-response relationship was observed between low economic level and high HBsAg prevalence that the adjust difference increased from 15.6% (aOR=1.156, 95% CI: 1.064–1.257) in the high-economic group to 46.3% (aOR=1.463, 95% CI: 1.294–1.824) in the lowest-economic group, compared with the highest-economic group. The association between low economic level and high HBsAg prevalence was stable in the sensitivity analysis. Interpretation: HBV infection was more concentrated among population with lower economic status. Economic-related inequalities in HBV infection decreased in the past decade. Our findings highlight the importance of developing equity-oriented policies and targeted interventions to reduce HBV infection among the poor and hard-to-reach populations to achieve the 2030 HBV elimination goals on time. Funding: National Natural Science Foundation of China.