Documentation discrepancies of time-dependent critical events in out of hospital cardiac arrest.

OBJECTIVES: The timing of and interval between events in prehospital care is important for system design, patient outcome, and prehospital research. Since these data can guide treatment recommendations, it is imperative that time-based prehospital documentation is accurate and precise, especially for time-sensitive conditions such as out-of-hospital cardiac arrest (OHCA). We compared the times of select events documented in the medical record (PCR) with times from time-stamped audio recordings in the monitor-defibrillator (AUD).
METHODS: A retrospective cohort of prehospital, adult, atraumatic OHCA resuscitations from two regional EMS agencies over a 10-month period was performed. Primary outcome was absolute difference (minutes) between PCR and AUD documented times for select events during OHCA resuscitation (IV access, IO access, first epinephrine administration, supraglottic airway insertion, endotracheal intubation, and return of spontaneous circulation). We describe the magnitude and direction of differences, and estimate the potential error in time intervals abstracted from the medical record.
RESULTS: Of 411 patients treated by EMS, 192 had complete data for ≥1 event and 136 had complete data for ≥2 events. 422 total events were identifiable in both PCR and AUD. Median absolute time discrepancy between PCR and AUD was 2 (IQR 1-4) min. Median differences between the smallest and largest PCR-AUD discrepancy was 2 (IQR 1-4.5) min. Discrepancies were both positive and negative, and not consistent within individual records.
CONCLUSION: We found a 2 (IQR 1-4) min imprecision in the documented timing of select events during OHCA resuscitation. This imprecision contributes to uncertainty in analyses that incorporate time-stamped variables.