BACKGROUND:
A recent study by the Centers for Disease Control and Prevention (CDC) and Abt Associates provides a unique opportunity to compare two sources of young children’s immunization data – the National Immunization Survey (NIS) provider reports, and state/local registries.

OBJECTIVE:
An objective was to compare provider- and registry-reported vaccination histories for a sample of children ages 19-35 months in four mature immunization registries. We studied vaccination types and doses that appeared in one data source but were missing from the other to help identify subgroups where these data were more likely to be absent.

METHOD:
Two groups were evaluated for this analysis, children with (1) provider-reported data, but some or all of the registry-reported vaccination doses were missing, and (2) registry-reported vaccination data, but some/all of the provider-reported doses were missing. Findings presented are for selected missing vaccination and dose data, and include characteristics of the children with missing vaccination history data and their providers.

RESULT:
Preliminary analysis of data for children from the four sites (n=323) for the diphtheria, tetanus, and pertussis series (4+ DTP) showed that among children with missing registry data (n=75, 23%), most had shot cards (68%), private providers (68%), a single provider (61%), and had providers who reported to registries (65%). Children with incomplete provider data (n=16, 5%) showed lower percentages for the first three indicators (31%, 63%, and 56% respectively), but had a higher percentage of providers (69%) who reported to registries. Also, for these children, the fourth provider-reported DTP dose tended to be missing.

CONCLUSION:
Registries were more likely to have missing vaccinations and doses than providers, however some registries had better data quality than others. Examination of DTP identified some potential data quality indicators and issues.

LEARNING OBJECTIVES:
Compare the quality of vaccination data from registries to the data from children’s providers.