Streitberger 2004.

Methods	Parallel‐group randomized trial, conducted in Germany. Study was conducted between January and August 2002.
Participants	212 women undergoing gynaecological or breast surgery under general anaesthesia. Exclusion: acupuncture treatment during the last 6 months, pregnancy, nausea or vomiting during the past 24 h, lymphoedema of the upper limbs, eczematous skin changes at the P6 acupoint, and coagulopathy. 1 woman in the acupuncture group withdrew consent and was treated as a failure in the analysis.
Interventions	Acupuncture group: 52 participants had acupuncture to P6 acupoint on both wrists, 20 min before induction of anaesthesia; another 54 participants had acupuncture to P6 acupoint on both wrists immediately after induction of anaesthesia. Sham acupuncture: 51 participants had placebo acupuncture to P6 acupoint on both wrists, 20 min before induction of anaesthesia; another 55 participants had placebo acupuncture to P6 acupoint on both wrists immediately after induction of anaesthesia.
Outcomes	Nausea (0 ‐ 24 h), vomiting (0 ‐ 24 h), risk of rescue antiemetic drugs, adverse events related to acupuncture.
Notes	Dimenhydinate and dolasetron rescue antiemetics used. Haematomas reported by 1 participant in the acupuncture group and by 2 participants in the placebo acupuncture group. Allergy to sticky plaster reported by 5 participants in each group. No severe adverse reaction reported. Funding source from University of Heidelberg (grant number F.203583). No details about any declarations of interest among authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"The patients were randomly distributed by type of surgery (gynaecological or breast) to ensure balance between groups". Comment: no further details provided in the paper.
Allocation concealment (selection bias)	Low risk	"The acupuncturist obtained randomisation allocation by phone from a member of the Coordination Centre for Clinical Trials, University of Heidelberg, who had no contact with study patients. An adequate concealment was thereby assured".
Blinding of patients (performance bias) All outcomes	Low risk	Authors took adequate steps to make interventions appear similar. To assess blinding, patients were asked what kind of needle they believe they had received".
Blinding of healthcare providers (performance bias) All outcomes	Low risk	"The patients, the observer of the endpoints, the nurses, the anaesthetists and all other staff members were not informed about the allocation".
Blinding of outcome assessor (detection bias) All outcomes	Low risk	"The patients, the observer of the endpoints, the nurses, the anaesthetists and all other staff members were not informed about the allocation".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Reasons for withdrawals given. Intention‐to‐treat analysis used.
Selective reporting (reporting bias)	Low risk	All expected outcomes reported.
Other bias	Low risk	Baseline characteristics were comparable. "Baseline characteristics revealed no relevant differences between the two groups (table 1)".