Jokela 2002.

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): NA Received treatment (n): NA Analysed (n): 60 Age (mean ± SD, median (IQR), median (range)): 51 ± 13 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 26 ± 5 ASA I/II/III/IV (n): 45/48/7/0 Gender (female in %): 100 Non‐smoker (%): 80 History of PONV/motion sickness (%): 71.6/33.3 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 123 Use of perioperative opioids (if yes, which?): 6.0 µg/kg fentanyl intraoperative, 0.33 mg/kg oxycodone postoperative Type of surgery: thyroid or parathyroid surgery Tropisetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 60 Age (mean ± SD, median (IQR), median (range)): 49 ± 14 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 26 ± 5 ASA I/II/III/IV (n): 52/38/10/0 Gender (female in %): 100 Non‐smoker (%): 66.6 History of PONV/motion sickness (%): 76.6/30 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 108 Use of perioperative opioids (if yes, which?): 5.3 µg/kg fentanyl intraoperative, 0.35 mg/kg oxycodone postoperative Type of surgery: thyroid or parathyroid surgery Metoclopramide Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 59 Age (mean ± SD, median (IQR), median (range)): 47 ± 13 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 26 ± 5 ASA I/II/III/IV (n): 64/31/5/0 Gender (female in %): 100 Non‐smoker (%): 84.7 History of PONV/motion sickness (%): 71.1/49.1 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 111 Use of perioperative opioids (if yes, which?): 5.9 µg/kg fentanyl intraoperative, 0.34 mg/kg oxycodone postoperative Type of surgery: thyroid or parathyroid surgery Included criteria: adult, ASA I to III, female, scheduled for thyroid or parathyroid surgery Excluded criteria: NA Pretreatment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV/motion sickness, perioperative opioids): no
Interventions	Intervention characteristics Ondansetron Dose: 16 mg Time point of administration: 1 hour before the operation Route of administration: PO Rescue antiemetics (if yes, which?): (64%) droperidol 0.75 mg IV Tropisetron Dose: 5 mg Time point of administration: 1 hour before the operation Route of administration: PO Rescue antiemetics (if yes, which?): (50%) droperidol 0.75 mg IV Metoclopramide Dose: 10 mg Time point of administration: 1 hour before the operation Route of administration: PO Rescue antiemetics (if yes, which?): (71%) droperidol 0.75 mg IV
Outcomes	Nausea (0 to 24 hours) Outcome type: dichotomous outcome Complete response (no PONV) in 24 hours Outcome type: dichotomous outcome Headache (0 to 24 hours) Outcome type: dichotomous outcome Visual disturbances (e.g. blurred vision) (0 to 24 hours) Outcome type: dichotomous outcome
Identification	Sponsorship source: NA Country: Finland Setting: inpatient, multi‐centre (3) Author's name: Ritva Jokela Institution: Department of Anaesthesia and Intensive Care, Helsinki University Email: ritva.m.jokela@hus.fi Address: Department of Anaesthesia and Intensive Care, Helsinki University, PB 140 (Haartmaninkatu 2), FIN‐00029 HUCH, Finland Duration of study: NA Language: English Study's primary outcome: PONV Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "the patients were randomly assigned (sealed envelope technique)" Judgement comment: no further information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: stated: "sequentially numbered, opaque, and sealed envelopes" (SNOSE)
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: no statement
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "a study nurse or one of the investigators interviewed the patients after 2 hours in the PACU and after 24 hours on the ward" Judgement comment: no statement on blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "we enrolled 200 patients in the study. Six patients were excluded as a result of a reoperation during the study period and 15 patients because of protocol violations. In the final analysis we had 179 patients: 60 in the ondansetron (Group O) and tropisetron (Group T) groups, and 59 in the metoclopramide (Group M) group. One hundred and sixteen patients were studied at Oulu University Hospital, 37 at Lapland Central Hospital, and 26 at Kuopio University Hospital"
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	Low risk	Judgement comment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV/motion sickness, perioperative opioids): no