Diagnosis of out-of-hospital cardiac arrest by emergency medical dispatchers: a diagnostic accuracy study

Introduction:This study was conducted to assess the diagnostic accuracy of out-of-hospital cardiac arrest (OHCA) made by emergency medical dispatchers (EMDs) in Tehran, Iran.Methods: Patients more than ۱۸ years of age who were suspected of having an OHCA by EMDs or emergency medical service (EMS) technicians at the patient’s bedside were eligible for inclusion in the study. The initial diagnosis, results of primary assessment and monitoring, and the final outcome of the mission (gold standard) were all recorded. Related archived audios were extracted from the system and listened to by the researcher (MM). Other required data were extracted from EMS mission forms and recorded in a prepreparedchecklist. After statistical analysis the accuracy was calculated.Results: A total of ۴۷۳۲ patients were included (mean age ۶۸.۱ ± ۱۹.۷ years) of which ۲۸۳۰ (۵۹.۸%) were men. These cases reported by ۱۷۳ EMDs that the EMDs mean age was ۲۷.۷±۳.۷ years, and they were all women. Cardiac arrest prevalence based on final diagnosis (gold standard) was ۳۷.۴% (۹۵% CI: ۳۶.۰–۳۸.۸). Sensitivity and specificity of OHCA diagnosis by EMDs was ۷۸.۶% and ۹۲.۴%, respectively. Positive predictive value, negative predictive value and accuracy were ۸۶.۱% (۹۵% CI: ۸۴.۵–۸۷.۶), ۸۷.۸% (۹۵% CI: ۸۶.۸–۸۸.۸) and ۸۷.۳% (۹۵% CI: ۸۶.۳–۸۸.۲), respectively. The sensitivity of diagnosis increased with increasing EMD’s work experience and also increasing the number of reported OHCA cases.Conclusion: Based on the results, accuracy of OHCA diagnosis by EMDs was almost ۸۷%. It is likely that more experienced EMDs or those with more experience diagnosing OHCA are better at recognising OHCA.

Keywords:

emergency medical dispatcher , emergency medical services , diagnosis , out-of-hospital cardiac arrest