Patients’ preferences for enrolment into critical-care trials Academic Article uri icon

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  • BACKGROUND: Most critically ill patients are incapable of providing informed consent for research. OBJECTIVE: We sought to determine patients' preferences for different consent frameworks for enrolling incapable patients into critical-care trials. DESIGN: Prospective observational and structured interview study. SETTING: Five university-affiliated hospitals in Ontario. PATIENTS: Two-hundred and forty consecutive capable and consenting survivors of critical illness. INTERVENTION: Participants considered four frameworks for enrolling incapable patients into clinical trials using a baseline scenario and three permutations for: risk (very low vs. high), treatment type (new vs. currently available), and availability of substitute decision-maker (yes vs. no). MEASUREMENTS AND MAIN RESULTS: For each scenario, patients chose their preferred framework and rated the acceptability of each framework using a seven-point Likert scale. Most (180/240; 76%) patients selected "consent by substitute prior to enrolment" as their preferred framework; this also received the highest baseline acceptability ratings ("acceptable" or "highly acceptable" 207/240; 87%). Modifying risk or treatment type did not substantially change these ratings. A minority of patients rated delayed consent as unacceptable or highly unacceptable in both the baseline scenario (48/240, 20% delayed to substitute; 57/240, 24% delayed to patient) and when a substitute was unavailable (34/240; 15%). CONCLUSIONS: Most survivors of critical illness found the usual practice of obtaining informed consent from a substitute decision-maker prior to enrolment in a clinical trial to be acceptable. Nearly half of patients considered foregoing informed consent to be unacceptable, whereas a minority considered enrolment followed by delayed consent to be unacceptable even when a substitute was unavailable. These approaches should, therefore, only be considered when deviating from the usual practice of obtaining consent from a substitute decision-maker is truly justified, such as where treatments being tested need to be delivered as soon as possible in order to be effective.


  • Scales, Damon C
  • Smith, Orla M
  • Pinto, Ruxandra
  • Barrett, Kali A
  • Friedrich, Jan O
  • Lazar, Neil M
  • Cook, Deborah
  • Ferguson, Niall D

publication date

  • October 2009