Research participants' opinions of delayed consent for a randomised controlled trial of glucose control in intensive care

Critically ill patients are often unable to give informed consent to participate in clinical research. A process of delayed consent, enrolling patients into clinical trials and obtaining consent as soon as practical from either the participant or their substitute decision maker, has sometimes been used. The objective of this study was to determine the opinion of participants, previously enrolled in the NICE-SUGAR study, of the delayed consent process. This observational study was conducted from 2009 to 2010 in the ICU of a tertiary referral hospital in Australia. Participants who were enrolled in the NICE-SUGAR study with delayed consent who survived, were cognitively intact, and proficient in English were posted a questionnaire regarding their opinion of the delayed consent process. The questionnaire was returned by post, fax, email, or completed during a telephone interview. Of 298 eligible participants, 210 responded, with an overall response rate of 79 %. Delayed consent to participate in the NICE-SUGAR study was obtained from participants (57/210; 27.1 %) or the substitute decision maker (152/210; 72.4 %). Most respondents (195/204; 95.6 %) would have consented to participate in the NICE-SUGAR study if asked before enrolment; most (163/198; 82.3 %) ranked first "the person who consented on their behalf for the NICE Study" as most preferred to make decisions, should they be unable; and most (177/202; 87.6 %) agreed with the decision made by their relative. Delayed consent to participate in a clinical trial that includes critically ill patients is acceptable from research participant's perspectives.