Impact of Health Insurance Status on Vaccination Coverage in Children 19–35 Months Old, United States, 1993–1996

Abstract

Objectives. To show how health insurance (privately and publicly insured, insured and uninsured) relates to vaccination coverage in children 19–35 months old, and how this can be used to better target public health interventions. Methods. The National Health Interview Survey (NHIS) gathers information on the health and health care of the U.S. non-institutionalized population through household interviews. The authors combined immunization and health insurance supplements from the 1993 through 1996 NHIS, and classified children 19–35 months old by their immunization and insurance status. Results were compared using both bivariate and multivariate analyses, and the backwards stepwise selection method was used to build multivariate logistic regression models. Results. Uninsured children tended to have lower vaccination coverage than those who had insurance, either private or public. Among those with insurance, publicly insured children had lower vaccination coverage than privately insured children. Backwards stepwise regression retained insurance status, metropolitan statistical area, and education of responsible adult family member as major predictors of immunization. Factors considered but not retained in the final model included child race/ethnicity, family poverty index, and region of country. Conclusions. Insurance status was a critical predictor of vaccination coverage for children ages 19–35 months. After controlling for confounders, the uninsured were about 24% less likely to receive all recommended shots than the insured and, among the insured, those with public insurance were about 24% less likely to receive all recommended vaccines than those with private insurance.