Accuracy of EMS-recorded patient demographic data

Emergency medical services (EMS) research is frequently dependent on data recorded by prehospital personnel. Linking EMS information with hospital outcome depends on essential identifying data. We sought to determine the accuracy of these data in patients who activated EMS for chest pain and to describe the types of errors committed.

We performed a retrospective, consecutive case series study of all prehospital records for patients transported by the City of Pittsburgh Bureau of EMS (annual call volume, 60,000) for chest pain to three area hospitals during a three-month interval. Demographic data, including name, date of birth (DOB), and Social Security number (SSN), for each patient were extracted from the EMS record. These were compared to the definitive information in the hospital records.

360 prehospital records were examined, with 341 matches to hospital records. The correct patient name was recorded in 301 records (83.6%), the correct DOB was recorded 284 times (78.9%), and the correct SSN was recorded 120 times (33.3%). The overall error rate of demographic data recorded on EMS records was 73.9% (266/360). If SSN is not included as a demographic variable, then the overall error rate was 25.3% (91/360).

The use of EMS-generated demographic data demonstrates moderate agreement and linkage with hospital records. Name and DOB are more reliable data elements for matching than SSN. Future research should examine the impact of electronic medical records and EMS identification numbers on data reliability.