Schultz 2003.

Methods	Parallel‐group randomized trial, conducted in United States. Study conducted from July 1999 to August 2000.
Participants	103 women undergoing gynaecological surgery. Exclusions: pregnancy, surgery for cancer within the previous 5 years, chemotherapy or radiation therapy within 5 years, an antiemetic within 24 h before surgery, previous use of acupressure bands, or peripheral neuropathy. 40 women withdrew before completion of trial due to non‐administration of study drug and change in postoperative plans due to earlier hospital discharge.
Interventions	Group 1: droperidol 1.25 mg IV at induction and acupressure wristband at P6 acupoint on both wrists before surgery (worn up to 48 h after surgery) (n = 30). Group 2: droperidol 1.25 mg IV at induction and sham acupressure wristband at P6 acupoint on both wrists before surgery (worn up to 48 h after surgery). Sham acupressure wristband had flat button which did not exert pressure on P6 acupoint (n = 24). Group 3: normal saline IV at induction and acupressure wristband at P6 acupoint on both wrists before surgery (worn up to 48 h after surgery) (n = 24). Group 4: normal saline IV at induction and sham acupressure wristband at P6 acupoint on both wrists before surgery (worn up to 48 h after surgery) (n = 25).
Outcomes	Nausea (0 ‐ duration of hospital stay), vomiting (0 ‐ hospital stay).
Notes	Authors replied to our request for unpublished data for incidence of nausea and vomiting during hospital stay. Sea Bands were provided by manufacturer. No details about any declarations of interest among authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Used random‐number table.
Allocation concealment (selection bias)	Low risk	"Study envelopes with the appropriate acupressure band and drug preparation were prepared by the principal investigator and the study pharmacist....The packets were kept in a secure area of the surgical admitting department. The envelope, containing the study group designation, was opened by the admitting nurse...".
Blinding of patients (performance bias) All outcomes	Low risk	Authors took adequate steps to make interventions appear similar.
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	High risk	Although 40 women withdrew from the study, reasons were given. "There was no statistically significant difference in the age of the 103 women who continued in the study as compared with 40 women who did not complete the study". Of the 103 women recruited, 95 and 62 women had complete data for nausea and vomiting during hospital stay respectively. Comment: missing data likely to bias the summary effect measure.
Selective reporting (reporting bias)	High risk	Risk of side effects and use of rescue antiemetic drugs were not described in the paper.
Other bias	Low risk	Baseline characteristics appeared to be comparable. There was no difference among the groups for age, type of surgery, duration of surgery, duration of acupressure wristband use.