• Niall D Ferguson, Denise Foster, Canadian Critical Care Trials Group, Ellen McDonald, Orla M Smith, Diane Heels-Ansdell, Marlies Ostermann, Nicole Zytaruk, Deborah Cook, PROTECT Investigators, Karen Burns, Andrea Matte, Pauline Galt, Laurie Meade, Nicole O'Callaghan, Dorrilyn Rajbhandari, Ismael Qushmaq, PROTECT Research Coordinators, and Australian, New Zealand Intensive Care Society Clinical Trials Group.
• Interdepartmental Division of Critical Care, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
• J Crit Care. 2013 Feb 1;28(1):28-39.

BackgroundSuccessful completion of randomized trials depends upon efficiently and ethically screening patients and obtaining informed consent. Awareness of modifiable barriers to obtaining consent may inform ongoing and future trials.ObjectiveThe objective of this study is to describe and examine determinants of consent rates in an international heparin thromboprophylaxis trial (Prophylaxis for ThromboEmbolism in Critical Care Trial, clinicaltrials.gov NCT00182143).DesignThroughout the 4-year trial, research personnel approached eligible critically ill patients or their substitute decision makers for informed consent. Whether consent was obtained or declined was documented daily.SettingThe trial was conducted in 67 centers in 6 countries.Measurements And Main ResultsA total of 3764 patients were randomized. The overall consent rate was 82.2% (range, 50%-100%) across participating centers. Consent was obtained from substitute decision makers and patients in 90.1% and 9.9% of cases, respectively. Five factors were independently associated with consent rates. Research coordinators with more experience achieved higher consent rates (odds ratio [OR], 3.43; 95% confidence interval, 2.42-4.86; P < .001 for those with >10 years of experience). Consent rates were higher in smaller intensive care units with less than 15 beds compared with intensive care units with 15 to 20 beds, 21 to 25 beds, and greater than 25 beds (all ORs, <0.5; P < .001) and were higher in centers with more than 1 full-time research staff (OR, 1.95; 95% confidence interval, 1.28-2.99; P < .001). Consent rates were lower in centers affiliated with the Canadian Critical Care Trials Group or the Australian and New Zealand Intensive Care Society Clinical Trials Group compared with other centers (OR, 0.57; 95% confidence interval, 0.42-0.77; P < .001). Finally, consent rates were highest during the pilot trial, lowest during the initiation of the full trial, and increased over years of recruitment (P < .001).ConclusionsCharacteristics of study centers, research infrastructure, and experience were important factors associated with successfully procuring informed consent to participate in this thromboprophylaxis trial.Copyright © 2013 Elsevier Inc. All rights reserved.

13 keywords...

hide…