title: Utilization of prehospital dispatch protocols to identify low-acuity patients.
abstract: OBJECTIVE
  To describe the experience of a U.S. emergency medical services (EMS) agency utilizing a dispatch algorithm to identify low-acuity patients and determine whether secondary telephone triage by a nurse was associated with subsequent hospital admission among those patients.
  
  
  METHODS
  This was a retrospective study of all patients meeting the low-acuity Omega classification by the Medical Priority Dispatch System (MPDS) in a large urban EMS system, conducted in two phases. Patients were excluded from the study if a refusal for transport was obtained, the call was received from a third-party caller, the MPDS system was not used, the patient was being referred from a skilled nursing facility, school, or university nursing office or physician's office, or if the call was referred to the Carolina Poison Center. Patients were enrolled over two phases using two different versions of the MPDS protocol, and in phase 2 patients were offered the option of speaking with an advice-line nurse. The outcome of interest was emergency department disposition, classified as hospital admission or discharge home. Admission to an intensive care unit (ICU) bed was also collected as a subcategory of hospital admission.
  
  
  RESULTS
  Of the 1,862 patients in phase 1, 69.3% were discharged home from the emergency department, whereas in phase 2, 73.0% of the 1,078 patients were discharged home. Individuals were most frequently admitted to the hospital across both phases if they had a dispatch determinant of pregnancy, psychiatric/behavioral, fall, sick person. Hospital admission was also associated with receiving an EMS or emergency department procedure. There were 530 patients in phase 2 who underwent secondary triage by an advice-line nurse. Among this cohort of patients, 134 (25.3%) required subsequent hospital admission, with a further three (2.2%) requiring an ICU admission.
  
  
  CONCLUSIONS
  This study identified a method for classifying patients during the dispatch period as low-acuity while attempting to ensure that those individuals received the medical care that they needed.
authors.affiliation: Carolinas Medical Center, The Center for Prehospital Medicine and Mecklenburg EMS Agency, Charlotte, North Carolina 28232, USA. jonst@medic911.com
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Studnek
authors.forename: Lars
authors.initials: L
authors.lastname: Thestrup
authors.forename: Tom
authors.initials: T
authors.lastname: Blackwell
authors.forename: Barry
authors.initials: B
authors.lastname: Bagwell
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002985:Clinical Protocols / Q000592:standards*; D004631:Emergency Medical Service Communication Systems / Q000592:standards / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000458:organization & administration; D004638:Emergency Treatment / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011786:Quality Control; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D014218:Triage / Q000379:methods* / Q000706:statistics & numerical data; D055815:Young Adult