title: The "vertical response time": barriers to ambulance response in an urban area.
abstract: BACKGROUND
  Ambulance response time is typically reported as the time interval from call dispatch to arrival on-scene. However, the often unmeasured "vertical response time" from arrival on-scene to arrival at the patient's side may be substantial, particularly in urban areas with high-rise buildings or other barriers to access.
  
  
  OBJECTIVE
  To measure the time interval from arrival on-scene to the patient in a large metropolitan area and to identify barriers to emergency medical services arrival.
  
  
  METHODS
  This was a prospective observational study of response times for high-priority call types in the New York City 9-1-1 emergency medical services system. Research assistants riding with paramedics enrolled a convenience sample of calls between 2001 and 2003.
  
  
  RESULTS
  A total of 449 paramedic calls were included, with a median time from call dispatch to arrival on-scene of 5.2 minutes. The median on-scene to patient arrival interval was 2.1 minutes, leading to an actual response interval (dispatch to patient) of 7.6 minutes. The median on-scene to patient interval was 2.8 minutes for residential buildings, 2.7 minutes for office complexes, 1.3 minutes for private homes (less than four stories), and 0.5 minutes for outdoor calls. Overall, for all calls, the on-scene to patient interval accounted for 28% of the actual response interval. When an on-scene escort provided assistance in locating and reaching the patient, the on-scene to patient interval decreased from 2.3 to 1.9 minutes. The total dispatch to patient arrival interval was less than 4 minutes in 8.7%, less than 6 minutes in 28.5%, and less than 8 minutes in 55.7% of calls.
  
  
  CONCLUSIONS
  The time from arrival on-scene to the patient's side is an important component of overall response time in large urban areas, particularly in multistory buildings.
authors.affiliation: Department of Emergency Medicine, Long Island Jewish Medical Center, New Hyde Park, NY, USA. aresilv@aol.com
authors.forename: Robert A
authors.initials: RA
authors.lastname: Silverman
authors.forename: Sandro
authors.initials: S
authors.lastname: Galea
authors.forename: Shannon
authors.initials: S
authors.lastname: Blaney
authors.forename: John
authors.initials: J
authors.lastname: Freese
authors.forename: David J
authors.initials: DJ
authors.lastname: Prezant
authors.forename: Richard
authors.initials: R
authors.lastname: Park
authors.forename: Raymond
authors.initials: R
authors.lastname: Pahk
authors.forename: Djorge
authors.initials: D
authors.lastname: Caron
authors.forename: Sonia
authors.initials: S
authors.lastname: Yoon
authors.forename: Jonathan
authors.initials: J
authors.lastname: Epstein
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Richmond
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances / Q000706:statistics & numerical data* / Q000600:supply & distribution; D002648:Child; D002675:Child, Preschool; D004631:Emergency Medical Service Communication Systems; D004632:Emergency Medical Services / Q000706:statistics & numerical data* / Q000600:supply & distribution; D005160:Facility Design and Construction; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006798:Housing; D006801:Humans; D007223:Infant; D008875:Middle Aged; D009519:New York City; D011446:Prospective Studies; D013997:Time Factors; D013996:Time and Motion Studies; D019037:Urban Health Services / Q000145:classification / Q000706:statistics & numerical data* / Q000600:supply & distribution