Abstract
Context: Vaccination coverage rates can be improved through the application of complete and accurate immunization information systems (IISs).
Objective: Evaluate the completeness and accuracy of Wisconsin's IIS, the Wisconsin Immunization Registry (WIR).
Design: Cross-sectional evaluation, comparing vaccination medical records (MRs) from provider clinics with WIR records.
Participants: Medical records of patients born during 2009 were randomly selected from 251 Wisconsin clinics associated with the Vaccines for Children Program.
Main Outcome Measures: Completeness: percentage of patients with client records in the WIR, percentage of patients up-to-date (%UTD) with the 4:3:1:3:3:1:4 vaccination series, and percentage of patients' MR vaccinations matched by administration date (+/-10 days) and type to vaccinations documented in the WIR. Accuracy: percentages of matched vaccinations with the same administration date, same trade name (TN), and same lot number.
Results: Of the 1863 selected patient MRs, 98% (n = 1833) had WIR client records and 97% of their 30 899 vaccinations were documented in the WIR. The %UTD was 49.3% using the MR only, 76.5% using the WIR only, and 75.2% as estimated by the National Immunization Survey. Among matched vaccinations, 99% had the same administration date, 96% had the same TN, and 95% had the same lot number. Compared with patients from clinics that entered data into the WIR using data exchange from electronic health records, patients from clinics that entered data using the Web-based user interface were less likely to have client records in the WIR (odds ratio: 0.3; 95% confidence interval: 0.1-0.9) and less likely to have accurate TNs (odds ratio: 0.3; 95% confidence interval: 0.1-0.5).
Conclusions: The WIR was complete and accurate among this sample of children born during 2009 and provided a vaccination coverage assessment similar to the National Immunization Survey. Our results provide support for the expectation that meaningful use and other initiatives that increase data exchange from electronic health records to IISs will improve IIS data quality.