Resuscitation Outcomes Consortium (ROC) PRIMED cardiac arrest trial methods. Part 2: Rationale and methodology for "Analyze Later vs. Analyze Early" protocol

  • Stiell I
  • Callaway C
  • Davis D
 et al. 
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Objective: The primary objective of the trial is to compare survival to hospital discharge with modified Rankin score (MRS) ≤3 between a strategy that prioritizes a specified period of CPR before rhythm analysis (Analyze Later) versus a strategy of minimal CPR followed by early rhythm analysis (Analyze Early) in patients with out-of-hospital cardiac arrest. Methods: Design-Cluster randomized trial with cluster units defined by geographic region, or monitor/defibrillator machine. Population-Adults treated by emergency medical service (EMS) providers for non-traumatic out-of-hospital cardiac arrest not witnessed by EMS. Setting-EMS systems participating in the Resuscitation Outcomes Consortium and agreeing to cluster randomization to the Analyze Later versus Analyze Early intervention in a crossover fashion. Sample size-Based on a two-sided significance level of 0.05, a maximum of 13,239 evaluable patients will allow statistical power of 0.996 to detect a hypothesized improvement in the probability of survival to discharge with MRS ≤3 rate from 5.41% after Analyze Early to 7.45% after Analyze Later (2.04% absolute increase in primary outcome). Conclusion: If this trial demonstrates a significant improvement in survival with a strategy of Analyze Later, it is estimated that 4000 premature deaths from cardiac arrest would be averted annually in North America alone. © 2008 Elsevier Ireland Ltd. All rights reserved.

Author-supplied keywords

  • CPR
  • Cardiac arrest
  • Defibrillation
  • Prehospital

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  • Ian G. Stiell

  • Clif Callaway

  • Dan Davis

  • Tom Terndrup

  • Judy Powell

  • Andrea Cook

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