THE IMMUNIZATION OF CHILDREN ENROLLED IN THE SPECIAL SUPPLEMENTAL FOOD PROGRAM FOR WOMEN, INFANTS, AND CHILDREN (WIC) - THE IMPACT OF DIFFERENT STRATEGIES

Objective.-To assess the impact of different interventions to increase measles vaccination coverage among preschool children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (W IC). Design.-Public health intervention trial. Setting.-Six volunteer WIC sites in New York City. Study Participants.-Children aged 12 to 59 months presenting for WIC certification between April 1 and September 30, 1991, who were eligible for measles vaccination. Interventions.-T wo WIC sites were assigned at random to one of three immunization stra tegies: (1) escort: child was escorted to a nearby pediatric clinic fo r immunization; (2) voucher incentive: the family returned monthly, ra ther than every 2 months, to pick up WIC food vouchers until the child was immunized; or (3) referral: the family was passively referred for immunization. Main Outcome Measure.-Proportion of eligible children r eceiving measles vaccination. Results.-Of children eligible for measle s immunization, 74% (618/836) were immunized. Children at escort sites were 5.5 times (relative risk [RR]=5.5; 95% confidence interval [CI], 3.7 to 8.1) and those at voucher incentive sites were 2.9 times (RR=2 .9; 95% CI, 1,9 to 4.5) more likely to be immunized than children at r eferral sites. Children were immunized more rapidly at escort sites (m edian, 14 days) and voucher incentive sites (median, 26 days) than at referral sites (median, 45 days; P<.001). Conclusions.-Both escort and voucher incentive models resulted in more children being immunized mo re rapidly than passive referral. Because of ease of administration, v oucher incentives may be a more suitable immunization intervention for use at WIC sites, with addition of escort where feasible.