Mashour 2012

Methods	RCT
Participants	Country: USA N = 18836 9460, 9376 Inclusion criteria ‐Age more than 18 yr, ‐Anaesthesia using inhalational or intravenous technique ‐Surgery any surgical case that did not involve the forehead ‐Availability for follow‐up interviews Exclusion criteria ‐intracranial procedures ‐adhesive allergy ‐psychosis, or history of traumatic brain injury
Interventions	1. BIS group: electronic alerts in the event of median BIS values more than 60 2. ETAG group: electronic alerts for median age‐adjusted MAC level of less than 0.5
Outcomes	The incidence of definite intraoperative awareness (using modified intention‐to‐treat analysis)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization was performed using a random‐number, computer‐generated block scheme based on even or odd operating room number"
Allocation concealment (selection bias)	Low risk	"...practitioners were not made aware of the randomization scheme or dates for randomization change during the study."
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	"Of the 9,460 patients randomized to the BIS intervention and successfully interviewed, 3,384 or 36% did not have BIS data recorded because of technical issues described in Materials and Methods.This population was used for secondary analysis only as a post hoc control group because it had neither intervention;"
Selective reporting (reporting bias)	Low risk	Selective reporting (reporting bias)
Blinding of patients?	Low risk	"Patients, postoperative interviewers, and all case reviewers were blinded to group assignment"
Blinding of anaesthesiologists?	High risk	"Practitioners receiving pages regarding BIS or MAC values were not blinded to group assignment."
Blinding of outcome assessors?	Low risk	"Patients, postoperative interviewers, and all case reviewers were blinded to group assignment"