Pediatrics-May 2005
OBJECTIVE: The Balanced Budget Act of 1997 established the
State Children's Health Insurance Program (SCHIP), which makes health insurance
available to children in near-poor families who are ineligible for Medicaid.
SCHIP mandates that all state plans cover the cost and administration of
childhood vaccines. Whether SCHIP has narrowed immunization coverage rates
between near-poor and nonpoor children is unknown. The objective of this study
was to use data from the National Immunization Survey from 1995 to 2002 to
analyze changes in immunization coverage rates among poor, near-poor, and
nonpoor children before and after implementation of SCHIP. METHODS: A prepost
analysis was made of changes in immunization rates among poor, near-poor, and
nonpoor children before and after implementation of SCHIP in all 50 states and
28 Immunization Action Plan areas from 1995 to 2002. All children in the
National Immunization Survey for whom information on vaccinations was available
from the respondents' shot cards and/or from the children's immunization
providers (N = 264214) were studied. Up-to-date status for the 4:3:1 (4 doses of
diphtheria-tetanus toxoids-pertussis vaccine/3 doses of poliovirus vaccine/1
dose of measles-mumps-rubella vaccine) and the 4:3:1:3:3 (4 doses of
diphtheria-tetanus toxoids-pertussis vaccine/3 doses of poliovirus vaccine/1
dose of measles-mumps-rubella vaccine/3 doses of Haemophilus influenzae type B
vaccine/3 doses of hepatitis B vaccine) series as well at the hepatitis B and
varicella vaccines was measured. RESULTS: The probability that a poor or
near-poor child was up to date for the 4:3:1:3:3 vaccine series increased
approximately 11 percentage points after implementation of SCHIP. However, we
observed a similar increase for nonpoor children. The proportion of poor and
near-poor children who were up to date for the varicella vaccine increased
between 7 and 8 percentage points more than among nonpoor children after
implementation of SCHIP. Relative increases among poor and near-poor children
were greater in the 28 Immunization Action Plan areas, in states with high rates
of uninsured children, and among Hispanics. CONCLUSION: SCHIP seems not to be
associated with changes in the up-to-date status of poor and near-poor children
for the 4:3:1 and the 4:3:1:3:3 vaccine series. Vaccine coverage rates increased
broadly among all income groups between 1995 and 2002.