Zhu 2010.

Methods	Parallel‐group randomized trial, conducted in China. Study dates not reported.
Participants	120 women undergoing gynaecological laparoscopic surgery, ASA I ‐ II, for general anaesthesia.
Interventions	Group 1: dilute droperidol injected into bilateral P6 acupoints using an acupuncture needle at 20 min before surgery. Twisted needle at depth of 2.5 cm to 3 cm to get needling sensation, and retained for 10 min (n = 40). Group 2: 2.5 mg droperidol IV 20 minutes before surgery (n = 40). Group 3: no treatment.
Outcomes	Nausea (0 ‐ 24 h), vomiting (0 ‐ 24 h), side effects of droperidol.
Notes	No treatment data were excluded from analysis. No drowsiness, anxiety or extrapyramidal reactions observed in any groups. No details about any declarations of interest among authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomized into 3 groups using a random‐numbers table.
Allocation concealment (selection bias)	Unclear risk	Sequential but no other details given.
Blinding of patients (performance bias) All outcomes	High risk	Participants unlikely to be blinded as they were conscious in order to feel needling sensation of acupuncture.
Blinding of healthcare providers (performance bias) All outcomes	High risk	No attempt to mask sham acupuncture in droperidol group.
Blinding of outcome assessor (detection bias) All outcomes	Unclear risk	Insufficient details given.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data recorded for 120 participants analysed.
Selective reporting (reporting bias)	Low risk	All expected outcomes reported.
Other bias	Low risk	Age and type of surgery among groups were comparable.