Barsoum 1990.

Methods	Parallel‐group randomized trial, conducted in England. Study dates not reported.
Participants	162 people undergoing general surgery. 10 participants withdrew because of language or age difficulty with completing analogue score, premature removal of wristbands, and incomplete follow‐up data.
Interventions	Acupressure wristbands placed on P6 acupoint of both wrists in the recovery room (n = 49). Sham acupressure wristbands (no studs) were applied to both wrists in the recovery room and antiemetics given only if clinically required (n = 54). Antiemetic group was given prochlorperazine 12.5 mg IM with each postoperative opiate injection and when clinically required, and wore an acupressure band without stud on both wrists in the recovery room (n = 49).
Outcomes	Vomiting (0 ‐ 24 h), risk of rescue antiemetic (prochlorperazine).
Notes	Nausea scores were reported for those participants who could not eat. Number of participants who were free of nausea was not given. Vomiting on postoperative day 2 and 3 also reported. 4 participants reported some local tightness and discomfort (1 of these experienced carpal tunnel‐like symptoms). 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	Low risk	Authors took adequate steps to make interventions appear similar and all participants were told that they were wearing wristbands to try to prevent PONV.
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	Reasons for withdrawals were given. No missing data reported for the 152 participants analysed.
Selective reporting (reporting bias)	High risk	Severity of nausea was reported but risk of nausea was not.
Other bias	Low risk	Baseline characteristics appeared to be comparable. "It can be seen that the groups were comparable with regard to the range of operation and anaesthetic agents used".