Kuvaki 1998.

Methods	Randomized controlled trial
Participants	ASA I‐II children from 2‐10 years old, undergoing inguinal hernia repair. Forty children divided into two groups of 20 No exclusion criteria given
Interventions	Experimental group: clonidine 2.5 μg/kg Control group: midazolam 0.5 mg/kg Premedications given rectally 30 min before the procedure
Outcomes	Pain as judged by a parental pain rating scale from 0‐3 Level of sedation Mask acceptance
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sealed envelopes drawn at random from a box
Allocation concealment (selection bias)	Low risk	Contents of the envelope read by an independent doctor, who administered the treatment as read and had no other involvement in the study
Blinding (performance bias and detection bias) All outcomes	Low risk	Investigators, patients and parents all blinded (information from original publication and from correspondence with Dr. Kuvaki)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only one patient excluded
Selective reporting (reporting bias)	Unclear risk	None evident
Other bias	Low risk	None evident; group demographics appear similar