Shen 2012.

Study characteristics
Methods	RCT.
Participants	Incluson criteria: Women undergoing elective CS N = 260 randomised, no exclusions but we will only use the data from 3 of the groups as our review does not include combination drugs so 195 in the analysis Exclusion criteria:
Interventions	Intervention 1: anticholinergic (Comparison 5) Scopolamine 0.3 mg/5 mL IV N = 65 Intervention 2: 5HT3 antagonist (Comparison 1) Ondansetron 4 mg IV N = 65 Intervention 3: anticholinergic + 5HT3 antagonist ‐ exclude as a combination of drugs Scopolamine+ondansetron N = 65 Comparator: placebo N = 65
Outcomes	Nausea and vomiting
Notes	Setting: not reported but authors from China‐Japan Frienship Hospital, Beijing, China Dates: not reported Funding source: not reported. Declaration of interest: not reported. English abstract only assessed, we will attempt to locate the full paper in English.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Only reported as “…randomly divided…”
Allocation concealment (selection bias)	Unclear risk	Not reported in abstract
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported in abstract
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported in abstract
Incomplete outcome data (attrition bias) All outcomes	Low risk	Seems clear that all participants provided data (e.g.. in table 3 the percentages are in brackets)
Selective reporting (reporting bias)	Unclear risk	Not possible to assess as we only have the English abstract at this point
Other bias	Unclear risk	Not possible to assess as we only have the English abstract at this point