Abd‐Elsayed 2012.

Methods	Randomised controlled trial
Data	Setting: secondary care in USA. 499 participants were eligible for 1 of 3 trials; all had substantial illness requiring major surgery (cardiac) at least 24 hours after being asked about consent
Comparisons	Investigated the use of different consent form presentations Intervention A: consent documents on heavy weight cream‐coloured paper (20‐pound) and a blue folder Comparator: consent documents as photocopies stapled together.
Outcomes	Proportion recruited to trial
Notes
Risk of bias
Item	Authors' judgement	Description
Random Sequence generation ok?	Yes	Adequate
Allocation concealment?	Yes	Adequate
Blinding of participants and personnel ok?	Unclear	Participants did not know there was a study. Personnel knew, and there was possibility that this could influence consent conversation, but there was substantial training so the effect is less clear.
Blinding of outcome assessment ok?	Yes	Participants were blind and data entered by someone who was blinded
Incomplete outcome data handled ok?	Yes	Adequate
Free of selective reporting?	Yes	Review only interested in recruitment, which is reported
Was the study free of other bias?	No	Trial stopped early because of host trials stopping early and consent responsibility for the third trial site moving to a different department
Overall bias?	Yes	High risk of bias