BACKGROUND AND AIMS: We examined the accuracy in assessments of emergency dispatchers according to their education and time of the day. We examined this in chest pain patients who were diagnosed with a potentially life-threatening condition (LTC) or died within 30days.

METHODS: Among 2205 persons, 482 died, 1631 experienced an acute coronary syndrome (ACS), 1914 had a LTC. Multivariable logistic regression was used to study how time of the call and the dispatcher's education were associated with the risk of missing to give priority 1 (the highest).

RESULTS: Among patients who died, a 7-fold increase in odds of missing to give priority 1 was noted at 1.00pm, as compared with midnight. Compared with assistant nurses, odds ratio for dispatchers with no (medical) training was 0.34 (95% CI 0.14 to 0.77). Among patients with an ACS, odds ratio for calls arriving before lunch was 2.02 (95% CI 1.22 to 3.43), compared with midnight. Compared with assistant nurses, odds ratio for operators with no training was 0.23 (95% CI 0.13 to 0.40). Similar associations were noted for those with any LTC. Dispatcher's education was not associated with the patient's survival.

CONCLUSIONS: In this group of patients, which experience substantial mortality and morbidity, the risk of not obtaining highest dispatch priority was increased up to 7-fold during lunchtime. Dispatch operators without medical education had the lowest risk, compared with nurses and assistant nurses, of missing to give priority 1, at the expense of lower positive predictive value.

KEY MESSAGES: What is already known about this subject? Use of the emergency medical service (EMS) increases survival among patients with acute coronary syndromes. It is unknown whether the efficiency - as judged by the ability to identify life-threatening cases among patients with chest pain - varies according to the dispatcher's educational level and the time of day. What does this study add? We provide evidence that the dispatcher's education does not influence survival among patients calling the EMS due to chest discomfort. However, medically educated dispatchers are at greatest risk of missing to identify life-threatening cases, which is explained by more parsimonious use of the highest dispatch priority. We also show that the risk of missing life-threatening cases is at highest around lunch time. How might this impact on clinical practice? Dispatch centers are operated differently all over the world and chest discomfort is one of the most frequent symptoms encountered; we provide evidence that it is safe to operate a dispatch center without medically trained personnel, who actually miss fewer cases of acute coronary syndromes. However, non-medically trained dispatchers consume more pre-hospital resources.