Evaluation of Intervention to Improve Immunization Up-to-Date Rates Among Children Attending WIC in South Los Angeles: Do Reminders Make a Difference?

Learning Objectives for this Presentation:
By the end of the presentation, participants will be able to:
1) describe an intervention designed to improve up-to-date (UTD) rates among children receiving services through WIC centers in South Los Angeles; and
2) describe the evaluation design and results.

Background:
: Ongoing interventions to improve childhood up-to-date rates at LA BioMed WIC sites in South Los Angeles include immunization screening and referral and a voucher incentive program. Funding from the California State Immunization Branch and the CDC REACH 2010 Initiative supported a supplemental intervention designed to identify children who were falling behind on the primary series of immunizations, and provide reminders by telephone and/or letter.

Objectives:
To evaluate the use of reminders from Community Health Outreach Workers (letters and telephone call) to improve pediatric immunization UTD rates.

Methods:
Between Jan and Dec 2006, 1250 children were randomly assigned to a control or intervention group. Participants were either 3 or 5 months of age and behind on at least one immunization. Both groups received the WIC-based interventions. The intervention group also received follow-up telephone calls and letters. Immunization rates were monitored through an electronic tracking system. Proportions up-to-date (3:2:2:2 series) and receipt of individual antigens were calculated at 7 months and 13 months for both groups. Chi-square analysis measured association between participation in the intervention and up-to-date status.

Results:
There was no significant difference in the overall UTD rate between groups at 7 or 13 months of age. Change in UTD rates between 7 and 13 months was not significantly associated with receipt of the intervention and there was no difference in rates for those receiving only a letter or only a telephone call.

Conclusions:
Supplemental reminder calls and/or letters in addition to ongoing WIC-based interventions did not significantly improve UTD rates in this urban population.