title: Briefer activation time is associated with better outcomes after out-of-hospital cardiac arrest.
abstract: Treatment of out-of-hospital cardiac arrest (OHCA) requires prompt intervention. Better outcomes are associated with briefer time from dispatch of emergency medical services (EMS) providers to arrival on scene, application of a defibrillator or insertion of an advanced airway. We assessed whether time from receipt of a call by a telecommunicator to dispatch of EMS providers was associated with outcomes.
  
  
  
  This was a retrospective analysis of a prospective cohort study of persons who had OHCA treated by EMS providers in Seattle, WA. Activation interval was defined as time from call pick up by telecommunicator to notification of EMS providers to respond to the call. Response interval was defined as the time from notification of EMS providers to their arrival at patient side. We determined the association between time intervals and outcomes of sustained restoration of spontaneous circulation (ROSC), survival to hospital discharge and neurologically favorable survival using multiple logistic regression. Secondary analyses assessed the relative contribution of activation versus response interval, and adjusted for post-treatment patient and EMS characteristics.
  
  
  
  Among 2,687 patients, activation interval was mean 1.2±0.6min. Response interval was mean 6.1±2.4min. 1,232 (45.9%) achieved ROSC; 475 (17.7%) survived to discharge; and 428 (15.9%) had favorable neurologic status at discharge. Compared to an activation interval of at least 1.5min, patients with briefer intervals were more likely to survive to discharge (adjusted odds ratio (OR) for <1min, 1.69 (95% confidence interval (CI), 1.26, 2.28); adjusted odds ratio for 1 to 1.49min, 1.54 (95% CI, 1.14, 2.08); p value=0.002). With baseline survival of 10%, the absolute increase in survival associated with a 30s decrease in activation interval was 0.7% and for a 30s decrease in response interval was 0.4%.
  
  
  
  Briefer activation interval was independently associated with greater survival. Further research is needed to assess whether reduction of the activation interval improves outcome after OHCA.
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States. Electronic address: nichol@uw.edu.
authors.forename: Graham
authors.initials: G
authors.lastname: Nichol
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Cobb
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yin
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Charles
authors.initials: C
authors.lastname: Maynard
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Michele
authors.initials: M
authors.lastname: Olsufka
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Larsen
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: McCoy
authors.affiliation: Medic One Support Group, Seattle Fire Department, University of Washington, Seattle, WA, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sayre
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods / Q000401:mortality; D000071820:Emergency Medical Dispatch / Q000379:methods; D004631:Emergency Medical Service Communication Systems / Q000458:organization & administration; D004632:Emergency Medical Services / Q000458:organization & administration / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D016019:Survival Analysis; D061665:Time-to-Treatment; D014861:Washington
keywords: Cardiac arrest; Epidmiology; Response time; Survival