KEYWORDS:
Immunization, WIC, evaluation, underserved

BACKGROUND:
Since 1996, CDC and six partner agencies have collaborated to improve pediatric vaccination coverage, focusing on WIC clinics as a key capture point. In 2000, President Clinton directed that the immunization-promoting activity of assessment and referral be institutionalized as part of the WIC certification process. In 2001, USDA issued a policy memorandum establishing minimum criteria for immunization assessment and referral. For those sites not counting all antigens in the vaccine series, DTaP could be used as a proxy for up-to-date (UTD) status, with immunization referral recommended only when deficiencies in the that series are noted.

OBJECTIVE(S):
To assess the sensitivity, specificity, and predictive values of the DTaP series as a predictor of UTD status for all pediatric immunizations; to forecast the efficacy of this approach in identifying underimmunized WIC enrollees.

METHOD(S):
Cross-sectional analysis of the National Immunization Survey 2000 Household and Provider records of children ages 3 months to 24 months who had ever been enrolled in WIC. UTD status for DTaP was compared with UTD status for all immunizations in the 4:3:1:3 series (4 DTaP, 3 polio, 1 MMR, 3 Hib). Internal predictive validity, predictive value positive and negative, sensitivity and specificity of the DTaP counts were the main outcome measures.

RESULT(S):
Sensitivity: 65%; specificity: 62%; predictive value positive: 88%; predictive value negative: 30% (preliminary calculations). Internal predictive validity and age-specific sensitivity, specificity, and predictive positive and negative values will be reported.

CONCLUSIONS(S):
Findings will be discussed in terms of their status as a baseline measure for assisting WIC clinics in building internal capacity and in developing achievable objectives in their efforts to improve immunization coverage in this vulnerable pediatric population.

LEARNING OBJECTIVES:
Project the potential of the WIC policy to accurately classify WIC enrollees’ immunization status.