title: Resuscitation Outcomes Consortium (ROC) PRIMED cardiac arrest trial methods part 1: rationale and methodology for the impedance threshold device (ITD) protocol.
abstract: OBJECTIVE
  The primary aim of this study is to compare survival to hospital discharge with a modified Rankin score (MRS)< or =3 between standard cardiopulmonary resuscitation (CPR) plus an active impedance threshold device (ITD) versus standard CPR plus a sham ITD in patients with out-of-hospital cardiac arrest. Secondary aims are to compare functional status and depression at discharge and at 3 and 6 months post-discharge in survivors.
  
  
  METHODS
  
  
  
  METHODS
  Prospective, double-blind, randomized, controlled, clinical trial.
  
  
  METHODS
  Patients with non-traumatic out-of-hospital cardiac arrest treated by emergency medical services (EMS) providers.
  
  
  METHODS
  EMS systems participating in the Resuscitation Outcomes Consortium.
  
  
  METHODS
  Based on a one-sided significance level of 0.025, power=0.90, a survival with MRS< or =3 to discharge rate of 5.33% with standard CPR and sham ITD, and two interim analyses, a maximum of 14,742 evaluable patients are needed to detect a 6.69% survival with MRS< or =3 to discharge with standard CPR and active ITD (1.36% absolute survival difference).
  
  
  CONCLUSIONS
  If the ITD demonstrates the hypothesized improvement in survival, it is estimated that 2700 deaths from cardiac arrest per year would be averted in North America alone.
authors.affiliation: Milwaukee, WI, USA. taufderh@mcw.edu
authors.forename: Tom P
authors.initials: TP
authors.lastname: Aufderheide
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kudenchuk
authors.forename: Jerris R
authors.initials: JR
authors.lastname: Hedges
authors.forename: Graham
authors.initials: G
authors.lastname: Nichol
authors.forename: Richard E
authors.initials: RE
authors.lastname: Kerber
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Davis
authors.forename: Ahamed H
authors.initials: AH
authors.lastname: Idris
authors.forename: Clifton W
authors.initials: CW
authors.lastname: Callaway
authors.forename: Scott
authors.initials: S
authors.lastname: Emerson
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Terndrup
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000295:instrumentation*; D004311:Double-Blind Method; D004554:Electric Countershock / Q000295:instrumentation*; D004632:Emergency Medical Services / Q000379:methods*; D006323:Heart Arrest / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D006801:Humans; D010043:Outcome and Process Assessment, Health Care; D010351:Patient Discharge / Q000706:statistics & numerical data*; D011446:Prospective Studies; D015996:Survival Rate