KEYWORDS:
Registry Modeling, Immunization Rates, Pockets of Need
BACKGROUND:
Registries are a growing tool for assessing population immunization levels. Traditionally surveys such as the National Immunization Survey have sampled local populations at some depth. Registries capture a larger population, but with less detail than surveys. Registries also capture those that are not compliant to surveys. One registry issue is partial capture of immunizations, leading to false negatives for UTD status. In contrast the problem of non-response in surveys tends to produce false positives. Consequently surveys and registries have limitations in determining immunization levels in sub-populations or pockets of need (PONs).
OBJECTIVE:
To produce a rigorous method for assessing immunization levels in sub-populations, based on either geographic or demographic features, such as county, race, or low-income status.
METHOD:
We developed a population-based model for estimating immunization rates using the Oregon ALERT registry. Data were drawn from the ALERT registry for the 4:3:1 series. Periodicity and patterns of missing shots were used to stratify the registry data. Modeling factors were chosen based on theoretical validity and independence. These factors include the likelihood of changes in providers, the chance of registry-capturing of data, starting late, and missed opportunities.
RESULT:
While approximately 80% of Oregon providers participate in the ALERT registry, initial results suggest that the registry captures over 90% of all immunizations. The apparent immunization rate for the state is corrected from these results, and rates for individual counties and selected sub-populations are generated.
CONCLUSION:
This approach can provide valuable information for public health practice in measuring sub-populations with limited immunizations, or identifying PONs.
LEARNING OBJECTIVES:
Participants will learn how this innovative approach has worked in Oregon, and how it can be applied to their own state registry data.
Back to Immunization Registries as Tools for Vaccination Coverage Assessment
Back to The 2003 Immunization Registry Conference (October 27-29, 2003)