#91 Counting the shots: A model for immunization assessment and referral in the wic setting

PURPOSE: Because children in poverty continue to be significantly under-immunized, WIC clinics, which are now the single largest point of access to these children, are crucial to assuring protection by vaccination. Realizing that comprehensive assessment of the immunization history of every child attending a WIC clinic exceeds the capacity of most local WIC clinics, a 7-member inter-agency collaboration led by the USDA and the CDC has proposed a simplified method in which the doses received of a single vaccine—the diphtheria-tetanus-pertussis (DTaP) series—are treated as a proxy for the entire 4-antigen 4:3:1:3 series (4 doses of DTaP, 3 of polio, 1 of measles-mumps-rubella, 3 of H influenza b). Because research has not yet shown whether childrenʹs true immunization status can be assessed accurately in this way, we evaluated the validity of DTaP as a predictor of completion status for the universally recommended 4:3:1:3 series. METHODS: We analyzed 6,277 records of WIC-enrolled children from the National Immunization Survey 2000 to index parentsʹ reports of completion status for DTaP as shown on the hand-held household record (Method 1); parentsʹ report of completion status for all immunizations in the 4:3:1:3 series (Method 2) based on the hand-held record; and providersʹ report of completion status for the 4:3:1:3 series (childʹs “true” immunization status). The comparative sensitivity, specificity, and overall test efficiency with which assessments based on Method 1 versus those based on Method 2 matched the provider-reported true immunization status were the main outcome measures. RESULTS: Although assessments based on the household-recorded DTaP count alone were 9% less sensitive than those based on the household-reported entire 4:3:1:3 series (74% vs. 83%, respectively), they were 6% more specific (93% vs. 87%). Overall test efficiency for the two methods (88% vs. 86%) was not significantly different. CONCLUSIONS: Results will be discussed in terms of their implications for developing achievable health objectives for this vulnerable population through the WIC-Immunization partnership.