Thompson 2000.

Methods	Randomisation: computer‐generated Allocation concealment: sealed opaque envelopes Blinding of participants/investigators: no Blinding of assessors: no No. randomised: 112 No. analysed: 112 Intention‐to‐treat analysis: yes Power and sample calculations described Duration of trial: not stated
Participants	Women undergoing outpatient oocyte recovery Mean age: 32 to 34 years Cause of infertility: not reported Similar baseline characteristics of age, height and weight, and history of previous oocyte recovery
Interventions	Control: patient‐controlled sedation and analgesia (inhalational isodesox via mask) (N = 57) Intervention: physician‐controlled sedation and analgesia (IV fentanyl 25 µg and midazolam 2 mg) (N = 55)
Outcomes	Primary: mean (unclear whether intraoperative or postoperative) pain score (VAS 0 to 100) Secondary: clinical pregnancy rate, side effects, patient satisfaction (Likert scale), adverse effects
Notes	Scotland Single centre Aberdeen University Funding: not stated Definition of pregnancy not documented
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated
Allocation concealment (selection bias)	Low risk	Adequate: sealed envelopes
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Blinding not possible owing to the nature of the interventions Blinding of assessors not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	All prespecified outcomes reported
Other bias	Low risk	Comparable demographic and infertility characteristics at baseline