Turner 1991.

Methods	Anaesthetic drugs used: propofol, N2O, O2 and isoflurane. Fentanyl 1microg/kg Premed‐induction interval: 60 (minutes)
Participants	74
Interventions	Drug(s) and dose: midazolam 10mg vs. temazepam 20mg vs. placebo
Outcomes	Memory, letter deletion 3 hours postoperatively
Notes	1) Patients' linear analogue scale showed both midazolam and temazepam better than placebo preoperatively 2) Difference from placebo? Not for memory. Temazepam group showed better performance on letter deletion than placebo ‐ authors suggest Type I error
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Method of randomization unknown
Allocation concealment?	Unclear risk	Not clear

DSST: Digital Symbol Substitution Test; Mins: Minutes; PACU: Post Anaesthesia Care Unit; STAI: State‐Trait Anxiety Inventory; TDT: Treiger Dot Test ; VAS: Visual Analogue Scale