Sadighha 2008.

Methods	Parallel‐group randomized trial, conducted in Iran. Study dates not reported.
Participants	156 adults undergoing elective laparoscopic cholecystectomy with ASA physical status I to II. Excluded: those with a history of PONV, kidney dysfunction, BMI > 35 kg/m², use of antiemetics or H₂ receptor antagonists within 72 hours of surgery, history of gastrointestinal disease, intra‐abdominal pressure > 15 mm Hg, or surgery duration of more than 2 h.
Interventions	Group 1: acupressure wristband at a P6 acupoint before induction until recovery discharge (n = 51). Group 2: metoclopramide 0.2 mg/kg IV at end of surgery and sham acupressure wristband at a non‐acupoint before induction until recovery discharge (n = 53). Group 3: no antiemetic and had sham acupressure wristband at a non‐acupoint before induction until recovery discharge (n = 52).
Outcomes	Nausea (recovery), vomiting (no time point specified).
Notes	Power calculation done. Funding source was Shaheed Beheshti University of Medical science. No details about any declarations of interest among authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"Patients were randomly assigned to treatment groups according to the last digit of the medical record number."
Allocation concealment (selection bias)	High risk	"Patients were randomly assigned to treatment groups according to the last digit of the medical record number."
Blinding of patients (performance bias) All outcomes	Low risk	Authors used sham acupressure and participants given general anaesthesia would not be aware of any antiemetic drugs given at end of surgery.
Blinding of healthcare providers (performance bias) All outcomes	Unclear risk	Insufficient details given.
Blinding of outcome assessor (detection bias) All outcomes	Low risk	"Assessors of nausea and vomiting were blinded to the treatment."
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data reported for 156 participants analysed.
Selective reporting (reporting bias)	High risk	No treatment side effects or rescue antiemetic use reported.
Other bias	Low risk	"Demographic and clinical characteristics of the three groups were similar."