Lazaraki 2007.

Methods	Single‐centre parallel‐group randomized controlled trial conducted in Greece in 2004
Participants	126 adults who were 23 to 84 years of age undergoing colonoscopy for the first time
Interventions	Intravenous administration of: 1) 25 ‐ 50 mcg fentanyl (mean 36 mcg) 2) 2 ‐ 5 mg midazolam (mean 4.6 mg)
Outcomes	Measured during the procedure: Discomfort, pain (0 = very well/no discomfort, 4 = unbearable) Incomplete procedures Vital signs Sedation reversal Measured after the procedure: Offset of sedation Participant satisfaction (measured in the trial as willingness to undergo another procedure with same medication) Anterograde amnesia (recalled procedures)
Notes	Conflicts of interest or funding sources were not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Monitoring was performed by a single specialist nurse blinded to the randomization
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Unclear risk	No clear evidence that measured outcomes were not reported (trial protocols were not sought for confirmation)
Other bias	Low risk	None expected