Article Text

Download PDFPDF
Controversial choice of a control intervention in a trial of ventilator therapy in ARDS: standard of care arguments in a randomised controlled trial
  1. H Mann
  1. Correspondence to:
 H Mann
 Department of Radiology, Program Associate, Division of Medical Ethics, 1A71 University Hospital, 50 North Medical Drive, Salt Lake City, UT 84132, USA;


When evaluating an innovative intervention in a randomised controlled trial (RCT), choosing an appropriate control intervention is necessary for a clinically meaningful result. An RCT reported in 2000 addressed the relative merits of two tidal volume ventilatory strategies, 6 ml/kg (innovative) and 12 ml/kg (control), in patients with acute respiratory distress syndrome. Critics claim that the 12 ml/kg volume did not represent the clinical practice standard at that time, and that lower tidal volumes had been used in some patients prior to randomisation. The trialists responded that current practice involved the use of a broad range of tidal volumes, including 12 ml/kg. Appropriate control interventions for RCTs can be ensured by: a systematic review of the relevant literature; a formal survey of expert clinicians; and publication of the proposed research protocol to solicit critical appraisal. A global survey of experts during the RCT’s design stage would have been of probative value in determining the appropriate control tidal volume. Hypothetical, but plausible, results of such a survey are presented and examined to demonstrate the value of this method.

  • control groups
  • ethical review
  • ethics committees
  • research
  • randomised controlled trials
  • survey

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.