Habib 2006.

Methods	Parallel‐group randomized trial, conducted in United States. Study dates not reported.
Participants	94 women undergoing Caesarean delivery under spinal anaesthesia. Exclusion: previous experience of acupuncture or acustimulation, had experienced vomiting or retching within 24 h before surgery, had taken on antiemetic or a glucocorticoid within 24 h before surgery, or had an implanted pacemaker or defibrillator device. 3 participants withdrew from study because of protocol violations.
Interventions	Transcutaneous acupoint electrical stimulation device on P6 acupoint of the dominant hand 30 ‐ 60 min before surgery. Participants asked to wear wristband for 24 h after surgery (n = 47). Sham transcutaneous acupoint electrical stimulation device on dorsum of wrist of the dominant hand 30 ‐ 60 min before surgery. Participants asked to wear wristband for 24 h after surgery (n = 44).
Outcomes	Postoperative nausea (0 ‐ 24 h), postoperative vomiting (0 ‐ 24 h), risk of rescue antiemetic.
Notes	Intraoperative nausea and vomiting data reported in the paper. Rescue antiemetic was ondansetron 4 mg IV if nausea score was 6 or more, or at participant's request. Study supported, in part, by departmental funds. 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	Insufficent information.
Allocation concealment (selection bias)	Unclear risk	Insufficient information.
Blinding of patients (performance bias) All outcomes	Low risk	Authors took adequate steps to make interventions appear similar. "For blinding, the ReliefBand was covered with opaque gauze that was taped to the wrist".
Blinding of healthcare providers (performance bias) All outcomes	Unclear risk	Insufficient information.
Blinding of outcome assessor (detection bias) All outcomes	Low risk	"A separate researcher who was unaware of the patient's randomisation collected that data...".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Reasons for withdrawals given. No missing data reported for 91 participants analysed.
Selective reporting (reporting bias)	High risk	Side effects not reported
Other bias	Low risk	Baseline characteristics were comparable. "The two groups were similar with respect to demographics, parity, history of PONV or motion sickness, smoking status, duration of surgery, blood loss, intraoperative fluids, intraoperative IV fentanyl, intraoperative IV ephedrine, treatment for pruritus, and consumption of oxycodone/acetaminophen tablets".