title: An evaluation of emergency medical services stroke protocols and scene times.
abstract: BACKGROUND
  Acute stroke patients require immediate medical attention. Therefore, American Stroke Association guidelines recommend that for suspected stroke cases, emergency medical services (EMS) personnel spend less than 15 minutes on-scene at least 90% of the time. However, not all EMS providers include specific scene time limits in their stroke patient care protocols.
  
  
  OBJECTIVE
  We sought to determine whether having a protocol with a specific scene time limit was associated with less time EMS spent on scene. Methods. Stroke protocols from the 100 EMS systems in North Carolina were collected and abstracted for scene time instructions. Suspected stroke events occurring in 2009 were analyzed using data from the North Carolina Prehospital Medical Information System. Scene time was defined as the time from EMS arrival at the scene to departure with the patient. Quantile regression was used to estimate how the 90th percentile of the scene time distribution varied by systems with protocol instructions limiting scene time, adjusting for system patient volume and metropolitan status.
  
  
  RESULTS
  In 2009, 23 EMS systems in North Carolina had no instructions regarding scene time; 73 had general instructions to minimize scene time; and 4 had a specific limit for scene time (i.e., 10 or 15 min). Among 9,723 eligible suspected stroke events, mean scene time was 15.9 minutes (standard deviation 6.9 min) and median scene time was 15.0 minutes (90th percentile 24.3 min). In adjusted quantile regression models, the estimated reduction in the 90th percentile scene time, comparing protocols with a specific time limit to no instructions, was 2.2 minutes (95% confidence interval 1.3, 3.1 min). The difference in 90th percentile scene time between general and absent instructions was not statistically different (0.7 min [95% confidence interval -0.1, 1.4 min]).
  
  
  CONCLUSIONS
  Protocols with specific scene time limits were associated with EMS crews spending less time at the scene while general instructions were not. These findings suggest EMS systems can modestly improve scene times for stroke by specifying a time limit in their protocols.
authors.affiliation: Received May 15, 2013 from the Departments of Epidemiology (MDP, KRE, WDR) and Biostatistics (CMS), Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; the Department of Emergency Medicine (JHB, CM), School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and SRA International (KMR), Durham, North Carolina. Revision received June 14, 2013; accepted for publication June 20, 2013.
authors.forename: Mehul D
authors.initials: MD
authors.lastname: Patel
authors.forename: Jane H
authors.initials: JH
authors.lastname: Brice
authors.forename: Chailee
authors.initials: C
authors.lastname: Moss
authors.forename: Chirayath M
authors.initials: CM
authors.lastname: Suchindran
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Rose
authors.forename: Wayne D
authors.initials: WD
authors.lastname: Rosamond
mesh_terms: D000465:Algorithms; D004632:Emergency Medical Services / Q000592:standards*; D017408:Guidelines as Topic; D006801:Humans; D009657:North Carolina; D012189:Retrospective Studies; D020521:Stroke / Q000175:diagnosis*; D013997:Time Factors
references.citation: Ann Emerg Med. 1999 Jan;33(1):3-8
references.pmid: 9867880
references.citation: Stroke. 2000 Nov;31(11):2585-90
references.pmid: 11062279
references.citation: Acad Emerg Med. 2003 Jul;10(7):789-97
references.pmid: 12837655
references.citation: Prehosp Emerg Care. 2013 Apr-Jun;17(2):170-6
references.pmid: 23216450
references.citation: Am J Emerg Med. 1988 Sep;6(5):443-8
references.pmid: 3415736
references.citation: J Emerg Med. 2009 Jul;37(1):40-5
references.pmid: 18722734
references.citation: Stroke. 2006 Jun;37(6):1508-13
references.pmid: 16690898
references.citation: Circulation. 2010 Oct 12;122(15):1464-9
references.pmid: 20876439
references.citation: MMWR Morb Mortal Wkly Rep. 2007 May 18;56(19):474-8
references.pmid: 17510611
references.citation: Stroke. 2006 Jan;37(1):263-6
references.pmid: 16339467
references.citation: Prehosp Emerg Care. 2005 Jan-Mar;9(1):19-23
references.pmid: 16036823
references.citation: Stroke. 2003 Apr;34(4):994-8
references.pmid: 12624218
references.citation: Prev Chronic Dis. 2009 Oct;6(4):A137
references.pmid: 19755013
references.citation: Stroke. 2009 Mar;40(3):754-6
references.pmid: 19118240
references.citation: Prehosp Emerg Care. 2010 Jan-Mar;14(1):85-94
references.pmid: 19947872
references.citation: Stroke. 2013 Mar;44(3):870-947
references.pmid: 23370205
references.citation: Stroke. 2001 Jan;32(1):63-9
references.pmid: 11136916
references.citation: Prehosp Emerg Care. 2001 Oct-Dec;5(4):335-9
references.pmid: 11642581
references.citation: Prehosp Emerg Care. 2013 Jan-Mar;17(1):38-45
references.pmid: 22913374
references.citation: Stroke. 2008 Dec;39(12):3262-7
references.pmid: 18688010
references.citation: Am J Crit Care. 2003 Sep;12(5):411-7
references.pmid: 14503424
references.citation: Stroke. 2007 Nov;38(11):3097-115
references.pmid: 17901393
references.citation: Stroke. 2005 Jul;36(7):1512-8
references.pmid: 15961712
references.citation: Prev Chronic Dis. 2009 Apr;6(2):A67
references.pmid: 19289010
references.citation: Ann Emerg Med. 1990 Feb;19(2):145-50
references.pmid: 2301791
references.citation: Stroke. 2013 Jan;44(1):270-7
references.pmid: 23238857