Leslie 2005a

Methods	RCT, multicentre
Participants	Country: Australia N = 2463 ASA: I/II/III/IV 111/179/542/388/5, 127/227/520/354/10 Gender: Male/Female 752/473, 784/454 Age: 58.1 (16.5), 57.5 (16.9) years Inclusion : at least one of risk factors for awareness, i.e. caesarean section, high risk cardiac surgery, acute trauma with hypovolaemia, rigid bronchoscopy, significant impairment of cardiovascular status, severe end stage lung disease, past history of awareness, unplanned awake intubation, known or suspected heavy alcohol intake, chronic benzodiazepine or opioid use , or current protease inhibitor therapy Operation: minor/intermediate/major 104/216/905, 104/231/903 Duration of anaesthesia: 3.2 (1.5‐4.4), 3.1 ( 1.3‐4.5) hours
Interventions	BIS‐guided anaesthesia (A‐2000, version 3.4, Aspect Medical Systems), a target BIS value of 40‐60 Routine anaesthesia (routine care group)
Outcomes	‐Confirmed awareness (Cn, %) ‐Recovery times*
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A computer‐generated random group allocation
Allocation concealment (selection bias)	Low risk	A central allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	" ..40 patients were withdrawn because of cancellation of surgery ( BIS group13, routine group13), withdrawal of consent ( six, twoO, surgery done without general anaesthesia ( four, none), or the patients was under‐age (none, two)" and " All patients.. were included in the intention‐to‐treat population for all analyses."
Selective reporting (reporting bias)	Low risk	All expected outcomes reported
Other bias	Unclear risk	The unblinded anaesthesiologist could potentially lead to ' learning contamination bias'
Blinding of patients?	Low risk	All patients were anaesthetized
Blinding of anaesthesiologists?	High risk	Unlikely to blind the anaesthesia providers to the allocated groups
Blinding of outcome assessors?	Low risk	"Follow‐up was undertaken by a blind observer."