White 2012.

Methods	Parallel‐group randomized trial, conducted in United States. Study dates not reported.
Participants	100 adult outpatients, with ASA physical status I ‐ II, undergoing major laparoscopic surgery. Exclusion criteria were people receiving antiemetic drugs within 24 hour before surgery, previous experience using acustimulation device for management of pain or emetic symptoms, history of alcohol or drug abuse within last 3 months, or a skin lesion or irritation at P6 acupoints.
Interventions	Group 1: Bilaterial acupressure (Pressure Right) strips on P6 acupoints 30 ‐ 60 min before entering operating room and left in place for 72 h after surgery. Dexamethasone 4 mg IV given before start of surgery, ondansetron 4mg IV given at end of surgery (n = 50). Group 2: Sham acupressure (no plastic button) strips on P6 acupoints 30 ‐ 60 min before entering operating room and left in place for 72 hours after surgery. Dexamethasone 4 mg IV given before start of surgery, ondansetron 4mg IV given at end of surgery (n = 50).
Outcomes	Nausea (0 ‐ 72 h), vomiting (0 ‐ 72 h), rescue antiemetic (metoclopramide 10 mg IV and prochlorperazine 25 mg suppository), side effects of acupressure.
Notes	Outcomes 0 ‐ 24 h also reported. Participants in the acupressure group were more likely to be highly satisfied with PONV management at 72 h than sham group (mean difference 18%, 95% CI 1% to 34%). No difference in 48 h or 72 h quality of recovery score between groups. "Incidence of side‐effects did not differ between the two study groups (Table 4)." Power calculation done. Active and sham Pressure Right acupressure devices were provided by manufacturer. Authors declare no conflicts of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation scheme.
Allocation concealment (selection bias)	Unclear risk	Insufficient details given.
Blinding of patients (performance bias) All outcomes	Low risk	Strips were identical.
Blinding of healthcare providers (performance bias) All outcomes	Low risk	Placement of acupressure or sham acupressure strips by co‐investigator not involved in outcome assessment.
Blinding of outcome assessor (detection bias) All outcomes	Low risk	Blinded observer questioned each participant before discharge and via telephone interviews about outcomes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	100 participants completed the study and all participants completed the follow‐up evaluations.
Selective reporting (reporting bias)	Low risk	All expected outcomes reported.
Other bias	Low risk	Demographic characteristics and history of PONV or motion sickness were not significantly different in the 2 antiemetic study groups.