Background Western countries report a significant increase in the proportion of patients who experience out-of-hospital cardiac arrests (OHCAs) and benefit from a public automated external defibrillator (pAED) before the arrival of rescue teams. However, recordings of devices recovered after resuscitation are of variable quality. Analysis of these data may inform decisions of whether to implement an internal defibrillator for survivors, and provide useful information about the performance of pAED algorithms and the actions of bystanders.

Objective To investigate the quality of the information recorded by pAEDs during OHCAs in the Paris area.

Methods pAED files used for some of the 8629 OHCAs that occurred in the greater Paris area between 1 January 2017 and 31 April 2019 on the day of the arrest were collected. The presence and accuracy of 23 factors required to interpret the recording was noted, including readability of the ECG, the presence of an impedance curve and the accuracy of the date and time. The recordings were analysed to assess the diagnostic and therapeutic performance of the pAEDs used.

Results A total of 258 patients with an OHCA received assistance from a pAED, and 182 recordings were recovered. The pAEDs were made by 12 different manufacturers. Data extraction required eight different transmission modes and 16 software programmes; recordings were of highly heterogeneous quality. Two per cent of the recordings were of such poor quality that they were not interpretable. Among the 98% remaining, only 43% included a thoracic impedance curve, 34% the intensity of the shocks delivered and 8% the patient name. The date and time were accurate in 68% and 48% of recordings, respectively. The pAEDs had 87.6% (95% CI 83.7% to 91.0%) sensitivity and 99.5% (99.5% to 99.5%) specificity for defibrillating shockable rhythms (positive predictive value 98.2% (96.4% to 99.0%), negative predictive value 96.4% (95.3% to 96.8%)). The absence of important variables prevented the analysis of approximately half of the inappropriate decisions made by pAEDs.

Conclusion Collection of pAED recordings is a major challenge. Their analysis is compromised by heterogeneity and poor quality (incomplete maintenance records, patient details and logs). AED recordings are currently the most relevant resource to track pAED performance and bystander practices. The quality of these recordings needs to improve.