title: Could a computer-based system including a prevalence function support emergency medical systems and improve the allocation of life support level?
abstract: OBJECTIVE
  To evaluate whether a computer-based decision support system could be useful for the emergency medical system when identifying patients with acute myocardial infarction (AMI) or life-threatening conditions and thereby improve the allocation of life support level.
  
  
  METHODS
  Patients in the Municipality of Göteborg who dialled the dispatch centre due to chest pain during a period of 3 months. To analyse the relationship between patient characteristics (according to a case record form used during an interview) and the response variables (AMI or life-threatening condition), multivariate logistic regression was used. For each patient, the probability of AMI/life-threatening condition was estimated by the model. We used these probabilities retrospectively to allocate advanced life support or basic life support. This model allocation was then compared with the true allocation made by the dispatchers.
  
  
  RESULTS
  The sensitivity, that is, the percentage of AMI patients allocated to advanced life support, was 85.7% in relation to the true allocation made by the dispatchers. The corresponding sensitivity regarding allocation made by the model was 92.4% (P=0.17). The specificity was also slightly higher for the model allocation than the dispatcher allocation. Among the 15 patients with AMI who were allocated to basic life support by the dispatchers, nine died (eight during and one after hospitalization). Among the eight patients with AMI allocated to basic life support by the model, only one patient died (in hospital) (P=0.02).
  
  
  CONCLUSIONS
  A computer-based decision support system including a prevalence function could be a valuable tool for allocating the level of life support. The case record form, however, used for the interview can be refined and a model based on a larger sample and confirmed in a prospective study is recommended.
authors.affiliation: Department of Informatics, University of Western Sweden, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Gellerstedt
authors.forename: Angela
authors.initials: A
authors.lastname: Bång
authors.forename: Johan
authors.initials: J
authors.lastname: Herlitz
mesh_terms: D022561:Advanced Cardiac Life Support; D000368:Aged; D020000:Decision Support Systems, Clinical; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D015276:Health Care Rationing / Q000379:methods; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D015995:Prevalence; D012680:Sensitivity and Specificity; D013548:Sweden; D014218:Triage / Q000379:methods*