Evaluation of Immunization Data Completeness Within a Large Community Health Care System Exchanging Data With a State Immunization Information System.

CONTEXT:: Information systems are used by most states to maintain registries of immunization data both for monitoring population-level adherence and for use in clinical practice and research. Direct data exchange between such systems and electronic health record systems presents an opportunity to improve the completeness and quality of information available. OBJECTIVE:: Our goals were to describe and compare the completeness of the Arizona State Immunization System- the electronic health record at a large community health provider in Arizona exchanging electronic data with the Arizona system- and personal immunization records in an effort to contribute to the discussion on the completeness of state-run immunization registries and data exchange with these registries. DESIGN:: Immunization histories from these sources were collected and reviewed sequentially. Unique dates of vaccination administrations were counted for each patient and tagged on the basis of comparisons across sources. RESULTS:: We quantified c