Wu 2007.

Study characteristics
Methods	Individual RCT
Participants	Inclusion criteria: Women undergoing elective CS under spinal anaesthesia. Contraindications including if regional anaesthesia contraindicated; allergy to dexamethasone, droperidol, opioids, local anaesthetics; established hypertension; or glucose intolerance; GI disease; administration of antiemetic in previous 24 hours. N = 120 women randomised, none were excluded after randomisation but we only used 3 groups in our analysis so we analysed data from 90 women. Exclusion criteria:
Interventions	Group 1: steroid (Comparison 3) Dexamethasone 8 mg. N = 30. Group 2: dopamine antagonist (Comparison 2) Droperidol 1.25 mg. N = 30. Group 3: steroid + Dopamine antagonist ‐ data nor used in this review Dexamethasone 4 mg + Droperidol 0.625 mg. N = 30. Group 4: Comparison: placebo Normal saline. N = 30.
Outcomes	Composite outcome of nausea and vomiting
Notes	Setting: Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan. Dates: not reported. Funding source: not reported. Declaration of interest: not reported. Only useable data are postoperative vomiting. Other outcomes are amalgamated in composite score. We have written to the authors and attempt to get separated data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer generated random numbers."
Allocation concealment (selection bias)	Unclear risk	No details.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Medications made up by uninvolved anaesthetist blinded to treatment
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Observers blinded to allocations.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up, ITT analysis.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Low risk	No baseline imbalance.