Ho 1990.

Methods	Parallel‐group randomized trial, conducted in Taiwan. Study dates not reported.
Participants	100 women undergoing laparoscopy.
Interventions	Group 1: electro‐acupuncture applied at P6 acupoint on right wrist for 15 min in the recovery room (n = 25). Group 2: transcutaneous electrical nerve stimulation at P6 acupoint on right wrist for 15 min in the recovery room (n = 25). Group 3: antiemetic group was given prochlorperazine 5 mg IV (n = 25). Group 4: no treatment (n = 25).
Outcomes	Vomiting (0 ‐ 3 h), side effects of treatment groups.
Notes	Reference group received no treatment and was not included in data analysis. Groups 1 and 2 were combined for data analysis, except for subgroup analysis on technique. Side effect of electro‐acupuncture were sleepiness and feeling tired. No details about funding source or any declarations of interest among authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information.
Allocation concealment (selection bias)	Unclear risk	Insufficient information.
Blinding of patients (performance bias) All outcomes	Unclear risk	Insufficient information.
Blinding of healthcare providers (performance bias) All outcomes	Unclear risk	Insufficient information.
Blinding of outcome assessor (detection bias) All outcomes	Unclear risk	Insufficient information.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data were reported for the 100 participants analysed.
Selective reporting (reporting bias)	High risk	Only vomiting was reported. Authors should have assessed nausea in women and the risk of rescue antiemetic drugs.
Other bias	Low risk	Baseline characteristics were comparable. "The age, weight, and duration of anaesthesia did not differ significantly among the groups".