What are the determinants of childhood immunization in the Philippines?

BACKGROUND: A key method of reducing morbidity and mortality is childhood immunization, yet in 2003, only 70% of Filipino children received all suggested vaccinations. Mortality rates have declined in recent years, though there remains one death for every 25 children under five years.

METHODS: Three separate outcomes of immunization status are investigated in this study: not immunized, partially immunized, and fully immunized. The Andersen Behavioral Model is the conceptual framework that was used for the study. Data were derived from the Women's Questionnaire of the 2003 Philippines National Demographic Health Survey, whose sample is comprised of 13,633 15-49 year old women. This survey employed a stratified three-stage cluster sampling design in each of the country's 17 administrative regions.

RESULTS: Multinomial logistic regression results indicate that in all three models (not immunized vs. partially immunized, not vs. fully, partially vs. fully), the odds of a child having a higher immunization status are significantly greater when pregnant mothers have attended at least the minimally-recommended four antenatal visits. Factors which were found to significantly improve the odds of improved immunization status in two models (not immunized vs. fully immunized, and partially vs. fully) included higher levels of maternal education, and greater household wealth.

CONCLUSION: Improving knowledge transfer to mothers is the most effective means by which to increase childhood immunization coverage. Antenatal visits provide an excellent opportunity for information sharing, and can be used to specifically target the mothers of children who are at greatest risk of being under-immunized.