Dewinter 2016.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 3 groups, monoprophylaxis
Participants	Baseline characteristics Ondansetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 200 Received treatment (n): 200 Analysed (n): 196 Age (mean ± SD, median (IQR), median (range)): 38 (32 to 49) Weight (mean ± SD, median (IQR), median (range)): 66 (59 to 74) BMI (mean ± SD, median (IQR), median (range)): 24 (21 to 26) ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): 76.4 History of PONV/motion sickness (%): 22/NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 108 Use of perioperative opioids (if yes, which?): 0.3 µg/kg sufentanil Type of surgery: laparoscopic gynaecological surgery Alizapride Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 200 Received treatment (n): 200 Analysed (n): 196 Age (mean ± SD, median (IQR), median (range)): 39 (31 to 50) Weight (mean ± SD, median (IQR), median (range)): 65 (60 to 74) BMI (mean ± SD, median (IQR), median (range)): 24 (22 to 27) ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): 75.9 History of PONV/motion sickness (%): 18.1/NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 95 Use of perioperative opioids (if yes, which?): 0.3 µg/kg sufentanil Type of surgery: laparoscopic gynaecological surgery Placebo Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 123 Received treatment (n): 123 Analysed (n): 123 Age (mean ± SD, median (IQR), median (range)): 39 (31 to 51) Weight (mean ± SD, median (IQR), median (range)): 65 (57 to 73) BMI (mean ± SD, median (IQR), median (range)): 23 (21 to 26) ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): 71 History of PONV/motion sickness (%): 19/NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 110 Use of perioperative opioids (if yes, which?): 0.3 µg/kg sufentanil Type of surgery: laparoscopic gynaecological surgery Included criteria: ASA I or II, women older than 18 years of age, scheduled for laparoscopic gynaecological surgery Excluded criteria: hypersensitivity to any of the study medications, ASA III to V, pregnancy, parkinsonism, mental disorders, psychiatric illness, consumption of antiemetic drugs within 24 hours before initiation of the study Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV, perioperative opioids): no; (history of motion sickness): unclear
Interventions	Intervention characteristics Ondansetron Dose: 4 mg Time point of administration: approximately 30 minutes before end of surgery Route of administration: IV Rescue antiemetics (if yes, which?): first‐line droperidol 1.25 mg and dexamethasone 5 mg IV; second‐line ondansetron 4 mg and alizapride 100 mg IV Alizapride Dose: 100 mg Time point of administration: approximately 30 minutes before end of surgery Route of administration: IV Rescue antiemetics (if yes, which?): first‐line droperidol 1.25 mg and dexamethasone 5 mg IV; second‐line ondansetron 4 mg and alizapride 100 mg IV Placebo Dose: saline Time point of administration: approximately 30 minutes before end of surgery Route of administration: IV Rescue antiemetics (if yes, which?): first‐line droperidol 1.25 mg and dexamethasone 5 mg IV; second‐line ondansetron 4 mg and alizapride 100 mg IV
Outcomes	Vomiting (PACU) Outcome type: dichotomous outcome PONV (0 to 24 hours) Outcome type: dichotomous outcome Adverse events (general notes in the publication, 24 hours' observation) Outcome type: general notes on side effects
Identification	Sponsorship source: none Country: Belgium Setting: inpatient and outpatient, single‐centre Author's name: Geertrui Dewinter Institution: Department of Anesthesiology, University Hospitals of the KU Leuven, Leuven, Belgium (SF) Email: geertrui.dewinter@uzleuven.be Address: Herestraat 49, Leuven 3000, Belgium Duration of study: November 2008 to July 2011 Language: English Study's primary outcome: incidences of PON (VAS score ≥ 1) and POV in PACU Trial registry number: EUCTR2008‐004789‐20
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomisation was performed using a computer‐generated randomisation code (Microsoft Excel)"
Allocation concealment (selection bias)	Low risk	Quote: "allocation concealment was ensured by enclosing assignments in sealed, opaque, sequentially numbered envelopes that were opened only after arrival of the patient in the operation room"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "patients, anaesthetists and the study nurse who collected the trial data were blinded to group allocation"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "patients, anaesthetists and the study nurse who collected the trial data were blinded to group allocation"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: reasons for exclusions were described and were unrelated to outcomes of interest
Selective reporting (reporting bias)	Unclear risk	Judgement comment: EUCTR2008‐004789‐20 (prospective registration). Timing of assessment of the primary outcome (PONV) was not defined in the protocol
Other bias	Unclear risk	Quote: "patients did not differ in respect of demographic/biometric data, risk factors for PONV, or durations of anaesthesia and surgery (Table 1). All patients received opioids perioperatively with no difference in opioid doses among the three groups" Judgement comment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV, perioperative opioids): no; (history of motion sickness): unclear