Accuracy of a state immunization registry in the pediatric emergency department

The purpose of this study was to ascertain whether either parental recall or a state immunization registry was as accurate as the medical record in determining immunization status in the emergency department (ED).

A convenience sample of children younger than 5 years who presented to the ED between July 2004 and May 2005 were enrolled prospectively. After obtaining informed consent, parents were asked about their child's immunization status. All children then had their immunization data accessed in the Arizona State Immunization Information System. The information obtained from the state registry, as well as the information from the parental interview, was then compared with the information on the medical record obtained from the primary care physician (PCP). Data were analyzed using simple descriptive statistics.

A total of 332 children were enrolled in the study. A total of 302 (91%) children enrolled were found in the state database, and 222 (74%) of these had a medical record available for comparison. The database agreed with the PCP record in 130 (59%) cases; parental report agreed with the PCP record in 149 (62%) cases.

Although most children can be found in the state immunization registry, it seems to be similar in accuracy to parental recall of immunization status when each is compared with the medical record. This may have been due to either underreporting of immunizations from the community or a delay in updating the state database. At this time, neither parental recall nor the database would accurately determine a child's immunization status during an ED visit.