title: Validation of using EMS dispatch codes to identify low-acuity patients.
abstract: OBJECTIVE
  To validate the predictive ability of previously derived emergency medical services (EMS) dispatch codes to identify patients with low-acuity illnesses.
  
  
  METHODS
  This prospective descriptive study was conducted in Rochester, New York. An expert panel reviewed and modified a previously derived set of low-priority EMS dispatch codes. Patients assigned these 21 codes between July 2002 and June 2003 were included for further analysis. Dispatch data and level of EMS care were recorded for each dispatch code. The proportion of low-acuity patients (i.e., those who received only basic life support (BLS) care or those who were not transported using lights and sirens) was determined using previously established definitions. Codes were defined as associated with low-acuity patients if the lower bound of the 95% confidence interval (CI) exceeded 90%. Medical records for patients identified as high-acuity were reviewed to evaluate whether the advanced life support (ALS) level care that was provided had a clinical impact.
  
  
  RESULTS
  Emergency medical services cared for 43,602 patients during the study, and 7,540 were dispatched as low-priority. We found that 7,197 (95%; 95% CI: 95-96%) of these patients met low-acuity criteria and that 11 of the evaluated codes were validated, with low-acuity care provided at least 90% of the time. Of the 343 patients identified as high-acuity, 62 (18%; 95% CI: 14-23%) were determined to have received interventions that had a clinical impact.
  
  
  CONCLUSIONS
  This study prospectively validates 11 EMS dispatch codes as being associated with low-acuity patients. These codes could be used to triage EMS patients based on dispatch information.
authors.affiliation: Department of Emergency Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York, USA. manish_shah@urmc.rochester.edu
authors.forename: Manish N
authors.initials: MN
authors.lastname: Shah
authors.forename: Paul
authors.initials: P
authors.lastname: Bishop
authors.forename: E Brooke
authors.initials: EB
authors.lastname: Lerner
authors.forename: Rollin J
authors.initials: RJ
authors.lastname: Fairbanks
authors.forename: Eric A
authors.initials: EA
authors.lastname: Davis
mesh_terms: D000208:Acute Disease / Q000145:classification; D016887:Cardiopulmonary Resuscitation; D015331:Cohort Studies; D016001:Confidence Intervals; D004630:Emergencies / Q000145:classification*; D004631:Emergency Medical Service Communication Systems / Q000592:standards*; D004632:Emergency Medical Services / Q000592:standards; D005260:Female; D005568:Forms and Records Control; D006801:Humans; D008297:Male; D011336:Probability; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D017749:Total Quality Management; D014218:Triage / Q000145:classification*