Gupta 2011.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 4 groups, monoprophylaxis, dose‐finding study
Participants	Baseline characteristics Ondansetron (group O1) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 34 Received treatment (n): 34 Analysed (n): 34 Age (mean ± SD, median (IQR), median (range)): 42 ± 0.2 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 23.4 ± 0.12 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 56 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 100 Use of perioperative opioids (if yes, which?): 225 µg intraoperative fentanyl Type of surgery: breast surgery, vaginal hysterectomy, skin grafting surgery, reconstructive limb surgery Ondansetron (group O4) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 34 Received treatment (n): 34 Analysed (n): 34 Age (mean ± SD, median (IQR), median (range)): 42 ± 1.4 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 22.6 ± 2.12 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 56 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 90 Use of perioperative opioids (if yes, which?): 235 µg intraoperative fentanyl Type of surgery: breast surgery, vaginal hysterectomy, skin grafting surgery, reconstructive limb surgery Ondansetron (group O8) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 34 Received treatment (n): 34 Analysed (n): 34 Age (mean ± SD, median (IQR), median (range)): 40 ± 5.3 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 22.6 ± 2.12 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 48 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 90 Use of perioperative opioids (if yes, which?): 200 µg intraoperative fentanyl Type of surgery: breast surgery, vaginal hysterectomy, skin grafting surgery, reconstructive limb surgery Placebo (group P) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 34 Received treatment (n): 34 Analysed (n): 34 Age (mean ± SD, median (IQR), median (range)): 40 ± 4.3 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 22.4 ± 1.2 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 60 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 90 Use of perioperative opioids (if yes, which?): 180 µg intraoperative fentanyl Type of surgery: breast surgery, vaginal hysterectomy, skin grafting surgery, reconstructive limb surgery Included criteria: adults of both sexes, ASA I and II, taking no prescription or over‐the‐counter medication, normal baseline electrocardiograms, posted for breast surgery, vaginal hysterectomy, skin grafting surgery, and reconstructive limb surgery Excluded criteria: known to have history of gastrointestinal disease; hormonal therapy; evidence of uncontrolled clinically important neurological, renal, hepatic, cardiovascular, metabolic, or endocrine dysfunction or clinically important abnormalities in laboratory screening tests; vomiting during the 24‐hour period before surgery; VAS > 4 at extubation if not extubated after 30 minutes following study medication; not responding to verbal commands after extubation; reaction to study drug; nasogastric tube in situ postoperatively; weighing 45 kg or > 90 kg; pregnant or lactating women Pretreatment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker): unclear; (perioperative opioids): yes
Interventions	Intervention characteristics Ondansetron (group O1) Dose: 1 mg Time point of administration: 30 minutes before extubation Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide 10 mg IV Ondansetron (group O4) Dose: 4 mg Time point of administration: 30 minutes before extubation Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide 10 mg IV Ondansetron (group O8) Dose: 8 mg Time point of administration: 30 minutes before extubation Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide 10 mg IV Placebo (group P) Dose: normal saline Time point of administration: 30 minutes before extubation Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide 10 mg IV
Outcomes	Adverse events (general notes in the publication, 24 hours' observation) Outcome type: general notes on side effects
Identification	Sponsorship source: nil Country: India Setting: single‐centre Author's name: Ranabir Pal Institution: Department of Community Medicine, Sikkim Manipal Institute of Medical Sciences and Central Referral Hospital, Gangtok, Sikkim Email: ranabirmon@yahoo.co.in Address: Department of Community Medicine, Sikkim Manipal Institute of Medical Sciences and Central Referral Hospital, 5th Mile, Tadong, Gangtok, Sikkim ‐ 737 102, India Language: English Duration of study: October 2008 to April 2009 Trial registry number: NA Study's primary outcome: incidence of PONV
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "the participants were randomly allocated into four groups with 34 participants in each group through a computer‐generated random number"
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "the anesthesiologist who administered the study drugs was blinded about the nature of treatment"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "intra‐operatively all the data were recorded by an independent observer blinded to the study drugs"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: no missing outcome data
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	High risk	Quote: "one hundred and thirty‐six adult participants of both sexes were comparable in terms of mean age, sex, Body Mass Index (BMI), and duration of anesthesia. There were no significant differences among the groups with respect to type of surgery performed (Chi square 0.5371, df 9, P=1.00) [Table 1]" Judgement comment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker): unclear; (perioperative opioids): yes