El‐Deeb 2011.

Methods	Parallel 3‐group randomized trial, conducted in Egypt. Study dates not reported.
Participants	450 women undergoing elective Caesaren delivery using spinal anaesthesia. Exclusion criteria: previous acupuncture treatment in the last 6 months, nausea or vomiting during 24 h preoperatively, diabetes, hypertension, cardiovascular disease, and any other major systemic comorbidities.
Interventions	Group 1: sham group (normal saline IV and sham electroacupuncture at dorsal side of forearm for 30 minutes) before spinal anaesthesia (n = 150). Group 2: ondansetron group (4 mg ondansetron IV 30 minutes and sham electroacupuncture at dorsal side of forearm for 30 minutes before spinal anaesthesia (n = 150). Group 3: electroacupuncture group (normal saline IV and electroacupuncture at P6 acupoint on both wrists for 30 minutes before spinal anaesthesia (n = 150).
Outcomes	Postoperative nausea (0 ‐ 6 h), postoperative vomiting (0 ‐ 6 h), rescue antiemetic (ondansetron 4 mg IV, 0 ‐ 6 h), treatment side effects.
Notes	"No local (cutaneous) side effects were reported at the acu‐stimulation site by any patient in the treatment groups during the 24h study period. No complications were noted". 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 details given.
Allocation concealment (selection bias)	Unclear risk	Sealed envelop used. Comment: not sure if envelopes were sequentially numbered and opaque.
Blinding of patients (performance bias) All outcomes	Low risk	Authors applied placebo drug and sham electroacupuncture techniques but blinding of participants not specified.
Blinding of healthcare providers (performance bias) All outcomes	Low risk	Authors applied placebo drug and sham electroacupuncture techniques but blinding of healthcare providers not specified.
Blinding of outcome assessor (detection bias) All outcomes	Low risk	Outcomes assessed by "independent anaesthetist who was blinded to group assignment".
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data reported for 450 participants analysed.
Selective reporting (reporting bias)	Low risk	All expected outcomes reported.
Other bias	Low risk	"The three groups were not significantly different with respect to demographic characteristics, intraoperative ephedrine dose, gestational age, and duration of surgery".