Evaluating the accuracy of transcribed computer-stored immunization data

To evaluate the accuracy of immunization records transcribed into a computer-based immunization tracking system and to assess factors that contribute to inaccurate or incomplete immunization record keeping.

Computer-stored immunization records were analyzed for 2098 children up to 2 years of age at the time of their most recent well-child visit to the UCLA Children's Health Center over a 12-month period. For children whose immunizations were not up to date, the computer-stored records were analyzed for sources of inaccuracy by comparison with the handwritten records from which the computer-stored data were transcribed.

An underimmunization rate of 22.5% (472 of 2098) was observed based on analysis of the computer-stored records. Comparison of the computer-stored and handwritten records revealed an overall transcription error rate of at least 10.2%. In addition, 38.4% of these apparently underimmunized children had received unrecorded immunizations from providers outside UCLA. When transcription errors were corrected and other available sources of immunization data were taken into account, the estimated rate of underimmunization decreased from 22.5% to 10.9%.

Unavoidable inaccuracies can diminish the utility of the data recorded in an immunization tracking system. Some inaccuracies are related to the process of transcription, but failures to record and communicate immunization data consistently also contribute to the inaccuracy of computer-stored immunization records.