Accuracy in identifying patients with loss of consciousness in a police-operated emergency call centre - first step in the chain of survival.

Abstract

The first link in the 'chain of survival' is the activation of Emergency Medical Services (EMS). In the major part of Denmark, police officers operate the alarm 1-1-2 centre, including calls for EMS. Our aim was to study the police 1-1-2 operators' accuracy in identifying calls concerning patients with loss of consciousness as a key symptom of life-threatening conditions. 'Unconsciousness' was defined as patients with a Glasgow Coma Scale (GCS) score of < 9, scored by the on-scene anaesthesiologist from the Mobile Emergency Care Unit (MECU). This study was an observational cohort study based on data from the Police 1-1-2 Database and the Aarhus County Pre-hospital Database containing data from MECU cases during 6 months in 2004-05. Two thousand, three hundred and forty-three emergency calls with MECU dispatch were identified. In 1655 cases, both 1-1-2 data and the GCS score were recorded. Two hundred and ninety-five patients were found with a GCS score of < 9 at MECU arrival, 243 of whom were reported 'unconscious' by 1-1-2, giving a sensitivity of 82%. One thousand, three hundred and sixty patients were found with a GCS score of > or = 9, 972 of whom were reported 'awake', giving a specificity of 72%. The positive predictive value (percentage of patients found with a GCS score of < 9 at MECU arrival amongst patients reported as 'unconscious') was 39%. The accuracy was moderate with room for improvement. The positive predictive value was low, indicating over-triage of MECU.