Out-of-hospital cardiac arrest diagnosis by emergency medical dispatchers; a diagnostic accuracy study


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

How to Cite

Saberian P, Sadeghi M, Hasani-Sharamin P, Modabber M, Baratloo A. Out-of-hospital cardiac arrest diagnosis by emergency medical dispatchers; a diagnostic accuracy study. Australasian Journal of Paramedicine [Internet]. 2019Sep.4 [cited 2022Jan.23];160. Available from: https://ajp.paramedics.org/index.php/ajp/article/view/691



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.


Patients more than 18 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 pre-prepared checklist. After statistical analysis the accuracy was calculated.


A total of 4732 patients were included (mean age 68.1 ± 19.7 years) of which 2830 (59.8%) were men. These cases reported by 173 EMDs that the EMDs mean age was 27.7±3.7 years, and they were all women. Cardiac arrest prevalence based on final diagnosis (gold standard) was 37.4% (95% CI: 36.0–38.8). Sensitivity and specificity of OHCA diagnosis by EMDs was 78.6% and 92.4%, respectively. Positive predictive value, negative predictive value and accuracy were 86.1% (95% CI: 84.5–87.6), 87.8% (95% CI: 86.8–88.8) and 87.3% (95% CI: 86.3–88.2), respectively. The sensitivity of diagnosis increased with increasing EMD’s work experience and also increasing the number of reported OHCA cases.


Based on the results, accuracy of OHCA diagnosis by EMDs was almost 87%. It is likely that more experienced EMDs or those with more experience diagnosing OHCA are better at recognising OHCA.



Ro YS, Shin SD, Song KJ, Cha WC, Cho JS. Triage‐based resource allocation and clinical treatment protocol on outcome and length of stay in the emergency department. Emerg Med Australas 2015;27:328-35.

Berdowski J, Berg RA, Tijssen JG, Koster RW. Global incidences of out-of-hospital cardiac arrest and survival rates: systematic review of 67 prospective studies. Resuscitation 2010;81:1479-87.

Zheng Z-J, Croft JB, Giles WH, Mensah GA. Sudden cardiac death in the United States, 1989 to 1998. Circulation 2001;104:2158-63.

Vaillancourt C, Stiell IG. Cardiac arrest care and

emergency medical services in Canada. Can J Cardiol 2004;20:1081-90.

Nichol G, Thomas E, Callaway CW, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA 2008;300:1423-31.

Ong MEH, Shin SD, Tanaka H, et al. Pan‐Asian Resuscitation Outcomes Study (PAROS): rationale, methodology, and implementation. Acad Emerg Med 2011;18:890-7.

Fothergill RT, Watson LR, Chamberlain D, et al. Increases in survival from out-of-hospital cardiac arrest: a five year study. Resuscitation 2013;84:1089-92.

Arhami Dolatabadi A, Kashani P, Hatamabadi H, Kariman H, Baratloo A. Using risk factors to help in the diagnosis of acute myocardial infarction in patients with non-diagnostic electrocardiogram changes in emergency department. Journal of Emergency Practice and Trauma 2015;1:3-6.

Stiell IG, Wells GA, Field B, et al. Advanced cardiac life support in out-of-hospital cardiac arrest. N Engl J Med 2004;351:647-56.

Viereck S, Møller TP, Rothman JP, Folke F, Lippert FK. Recognition of out-of-hospital cardiac arrest during emergency calls - a systematic review of observational studies. Scand J Trauma Resusc Emerg Med 2017;25:9.

Lewis M, Stubbs BA, Eisenberg MS. Dispatcher-assisted CPR: time to identify cardiac arrest and deliver chest compression instructions. Circulation 2013;128:1522-30.

Berdowski J, Beekhuis F, Zwinderman AH, Tijssen JG, Koster RW. Importance of the first link: description and recognition of an out-of-hospital cardiac arrest in an emergency call. ibid. 2009;119:2096-102.

Culley LL, Clark JJ, Eisenberg MS, Larsen MP. Dispatcher-assisted telephone CPR: common delays and time standards for delivery. Ann Emerg Med 1991;20:362-6.

Vaillancourt C, Verma A, Trickett J, et al. Evaluating the effectiveness of dispatch‐assisted cardiopulmonary resuscitation instructions. Acad Emerg Med 2007;14:877-83.

Altman D, Machin D, Bryant T, Gardner M. Statistics with confidence: confidence intervals and statistical guidelines. John Wiley & Sons; 2013.

Mercaldo ND, Lau KF, Zhou XH. Confidence intervals for predictive values with an emphasis to case-control studies. Stat Med 2007;26:2170-83.

Garza AG, Gratton MC, Chen JJ, Carlson B. The accuracy of predicting cardiac arrest by emergency medical services dispatchers: the calling party effect. Acad Emerg Med 2003;10:955-60.

Vaillancourt C, Charette M, Kasaboski A, et al. Cardiac arrest diagnostic accuracy of 9-1-1 dispatchers: a prospective multi-center study. Resuscitation 2015;90:116-20.

Viereck S, Moller TP, Rothman JP, Folke F, Lippert FK. Recognition of out-of-hospital cardiac arrest during emergency calls - a systematic review of observational studies. Scand J Trauma Resusc Emerg Med 2017;25:9.

Vaillancourt C, Charette ML, Bohm K, Dunford J, Castrén M. In out-of-hospital cardiac arrest patients, does the description of any specific symptoms to the emergency medical dispatcher improve the accuracy of the diagnosis of cardiac arrest: a systematic review of the literature. Resuscitation 2011;82:1483-9.

Nurmi J, Pettilä V, Biber B, et al. Effect of protocol compliance to cardiac arrest identification by emergency medical dispatchers. ibid. 2006;70:463-9.

Roppolo LP, Westfall A, Pepe PE, et al. Dispatcher assessments for agonal breathing improve detection of cardiac arrest. ibid. 2009;80:769-72.

Calle PA, Lagaert L, Vanhaute O, Buylaert WA. Do victims of an out-of-hospital cardiac arrest benefit from a training program for emergency medical dispatchers? ibid. 1997;35:213-8.

Besnier E, Damm C, Jardel B, et al. Dispatcher-assisted cardiopulmonary resuscitation protocol improves diagnosis and resuscitation recommendations for out-of-hospital cardiac arrest. Emerg Med Australas 2015;27:590-6.