title: Accuracy in identifying patients with loss of consciousness in a police-operated emergency call centre - first step in the chain of survival.
abstract: BACKGROUND
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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%.
  
  
  CONCLUSIONS
  The accuracy was moderate with room for improvement. The positive predictive value was low, indicating over-triage of MECU.
authors.affiliation: Aarhus University Hospital, Department of Anaesthesia and Intensive Care Medicine, Aarhus Traumacentre, Aarhus, Denmark. allanbach@dadlnet.dk
authors.forename: A
authors.initials: A
authors.lastname: Bach
authors.forename: E F
authors.initials: EF
authors.lastname: Christensen
mesh_terms: D015331:Cohort Studies; D016208:Databases, Factual; D003718:Denmark; D004630:Emergencies; D005188:False Negative Reactions; D005189:False Positive Reactions; D006323:Heart Arrest / Q000175:diagnosis; D006801:Humans; D016495:Police; D016019:Survival Analysis; D017741:Survivors; D013689:Telephone; D014474:Unconsciousness / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D014851:Wakefulness