Myles 1999.

Methods	Randomised controlled trial
Data	Setting: secondary care, Australia. 769 inpatients aged 18 or over, scheduled for elective surgery
Comparisons	Investigated the effect of different consent methods Intervention A: pre‐randomised to experimental drug and asked to provide consent; if no consent, standard treatment given Intervention B: pre‐randomised to standard drug and asked to provide consent; if no consent, experimental treatment given Intervention C: told that the physician thinks experimental drug superior, if consent given, has 70% chance of receiving this; if no consent, standard treatment given Intervention D: allowed to increase or decrease their chance of receiving the experimental drug if consent given, and if no preference, 50% chance of receiving it; if no consent, standard treatment given Compared to standard randomisation method (equal chance of experimental or standard drug)
Outcomes	Proportion recruited to hypothetical trial
Notes
Risk of bias
Item	Authors' judgement	Description
Random Sequence generation ok?	Unclear	Mentions randomisation but no details given
Allocation concealment?	Unclear	See above
Blinding of participants and personnel ok?	Unclear	Patient is blinded (they are not told the exact details of the study in the patient information). Researchers (probably) knew the allocation.
Blinding of outcome assessment ok?	Unclear	Outcome was subjective and unclear what potential researchers had to influence this while participants answered questions about intentions
Incomplete outcome data handled ok?	Yes	Adequate
Free of selective reporting?	Yes	Willingness to take part outcome presented, which is all the review needs
Was the study free of other bias?	No	Hypothetical trial
Overall bias?	Yes	High risk of bias