Context.— Inner-city immunization rates have lagged behind those in other areas
of the country.
Objective.— To evaluate the impact of an initiative linking immunization with distribution
of food vouchers in the inner city.
Design.— Retrospective analysis of immunization data gathered in 1996 and 1997.
Setting.— Nineteen Special Supplemental Nutrition Program for Women, Infants,
and Children (WIC) sites serving 30% of the Chicago, Ill, birth cohort.
Participants.— A total of 16581 children 24 months old or younger.
Interventions.— Voucher incentives (varying frequency of food voucher issuance based
on immunization status) and assessment of immunization status and referral
to immunization provider.
Main Outcome Measures.— Age-appropriate immunization rates and WIC enrollment rates.
Results.— During the 15-month period of evaluation, immunization rates increased
from 56% to 89% at sites performing voucher incentives. The proportion of
children needing voucher incentives declined from 51% to 12%. Sites performing
assessment and referral, but not providing voucher incentives, showed no evidence
of improvement in immunization coverage. No difference was observed in enrollment
rates between sites performing voucher incentives and those that did not.
Conclusion.— Applied in a large-scale, programmatic fashion, voucher incentives in
WIC can rapidly increase and sustain high childhood immunization rates in
an inner-city population.