Impact of antenatal care visits on childhood immunization: a propensity score-matched analysis using nationally representative survey.

BACKGROUND Evidence has suggested a relationship between antenatal care (ANC) visits and childhood immunization coverage. However, evaluating its impact using observational data suffers from the problem of selection bias. Hence, we adopted propensity score-matched (PSM) analysis for studying the impact of ANC visits on childhood immunization. METHODS Data regarding ANC visits and childhood immunization were collected from a nationally representative survey, National Family Health Survey-4 (NFHS-4). We performed PSM analysis with logit model using the psmatch2 command package in STATA to find the average treatment effect on the population (ATE), treated (ATT), and untreated (ATU). RESULTS In total, 5,430 participants were included in the analysis. Radius matching with caliper width of 0.01 was used to match the groups. The ATT values in the intervention and control groups were 0.71 and 0.47, respectively, indicating that the immunization coverage was increased by 24% because of ANC visits. The ATU values in the intervention and control groups were 0.40 and 0.65, respectively. This indicates that for the women who did not make the ANC visits, the chance of getting their children immunized would have increased by 25% if they had made four or more visits. The final ATE estimate was 0.25 among the study participants. Quality of matching was good with no significant difference in characteristics between the two groups. CONCLUSION Findings from our study imply that policymakers in India should focus on further improving the ANC coverage as it has a significant impact on improving childhood immunization coverage.