Grimsehl 2002.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, monoprophylaxis
Participants	Baseline characteristics Cyclizine Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 37 Received treatment (n): NA Analysed (n): 37 Age (mean ± SD, median (IQR), median (range)): 31 ± 6 Weight (mean ± SD, median (IQR), median (range)): 66 ± 11 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): 27/NA Type of general anaesthesia: inhalational anaesthesia (isoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 26 Use of perioperative opioids (if yes, which?): 1 µg/kg fentanyl, 7 patients with morphine IV and 16 patients with codeine PO as rescue analgesics Type of surgery: diagnostic laparoscopy or laparoscopic sterilisation Ondansetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 37 Received treatment (n): NA Analysed (n): 37 Age (mean ± SD, median (IQR), median (range)): 33 ± 5 Weight (mean ± SD, median (IQR), median (range)): 63 ± 11 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): 16/NA Type of general anaesthesia: inhalational anaesthesia (isoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 25 Use of perioperative opioids (if yes, which?): 1 µg/kg fentanyl, 9 patients with morphine IV and 19 patients with codeine PO as rescue analgesics Type of surgery: diagnostic laparoscopy or laparoscopic sterilisation Included criteria: ASA I and II, written informed consent, scheduled to undergo diagnostic laparoscopy or laparoscopic sterilization Excluded criteria: NA Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV, perioperative opioids): no; (history of motion sickness, non‐smoker): unclear
Interventions	Intervention characteristics Cyclizine Dose: 50 mg Time point of administration: at induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): 11%, prochlorperazine 12.5 mg IM Ondansetron Dose: 4 mg Time point of administration: at induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): 14%, prochlorperazine 12.5 mg IM
Outcomes	Vomiting (0 to 24 hours) Outcome type: dichotomous outcome Vomiting (0 to time to discharge) Outcome type: dichotomous outcome Vomiting (discharge to 24 hours) Outcome type: dichotomous outcome Nausea (0 to 24 hours) Outcome type: dichotomous outcome
Identification	Sponsorship source: NA Country: UK Setting: outpatient, single‐centre Author's name: K. Grimsehl Institution: Ninewells Hospital, Dundee DD1 9SY, UK Email: NA Address: Ninewells Hospital, Dundee DD1 9SY, UK Duration of study: NA Language: English Study's primary outcome: incidence of nausea Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly assigned by closed envelope technique" Judgement comment: insufficient information on random sequence generation
Allocation concealment (selection bias)	Unclear risk	Judgement comment: not stated; "sequentially numbered, opaque, and sealed envelopes" (SNOSE)
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: insufficient information on blinding ("double‐blind")
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "...mg diclofenac suppository was inserted. All assessments were carried out by a blinded investigator, who was unaware of the anti‐emetic given. Anaesthetic time was recorded as..."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "(Research Solutions Ltd, UK). Seventy‐four patients were recruited to the study and peri‐operative data were obtained for all subjects. Both groups were comparable for..." Judgement comment: at 24‐hour follow‐up: 12 patients were omitted (did not return questionnaire, required escape antiemetic, inadequate analgesia)
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	Unclear risk	Quote: "...obtained for all subjects. Both groups were comparable for patient characteristics, menstrual cycle, previous PONV and type of operation (Table 1). Anaesthetic times were similar in both groups, but mean (SD) time to..." Judgement comment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV, perioperative opioids): no; (history of motion sickness, non‐smoker): unclear