Blitz 2012.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, monoprophylaxis and combination prophylaxis
Participants	Baseline characteristics Palonosetron + dexamethasone Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 59 Received treatment (n): NA Analysed (n): 59 Age (mean ± SD, median (IQR), median (range)): 35.2 ± 8.8 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 37.8 ± 11.5 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 81.36 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): NA Use of perioperative opioids (if yes, which?): fentanyl during anaesthesia Type of surgery: laparoscopic abdominal or gynaecological surgery Palonosetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 59 Received treatment (n): NA Analysed (n): 59 Age (mean ± SD, median (IQR), median (range)): 36.2 ± 8.1 Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 36.6 ± 9.9 ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 88.14 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): NA Use of perioperative opioids (if yes, which?): fentanyl during anaesthesia Type of surgery: laparoscopic abdominal or gynaecological surgery Included criteria: ASA I and II, 3 or more risk factors for PONV, scheduled to undergo elective outpatient laparoscopic abdominal or gynaecological surgery under general anaesthesia Excluded criteria: pregnant or nursing mothers, received antiemetics within 24 hours of surgery, experienced retching or vomiting within 24 hours before surgery, on long‐term steroid therapy, were immunocompromised, documented allergy to 5‐HT3 receptor antagonists or dexamethasone Pretreatment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender): no; (history of PONV/motion sickness, duration of anaesthesia, non‐smoker, perioperative opioids): unclear
Interventions	Intervention characteristics Palonosetron + dexamethasone Dose: palonosetron 0.075 mg, dexamethasone 8 mg Time point of administration: immediately after induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): at the discretion of the patient's anaesthesiologist (no 5‐HT3 receptor antagonists) Palonosetron Dose: 0.075 mg Time point of administration: immediately after induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): at the discretion of the patient's anaesthesiologist (no 5‐HT3 receptor antagonists)
Outcomes	Vomiting (0 to 2 hours) Outcome type: dichotomous outcome
Identification	Sponsorship source: funding provided by Eisai Inc. Country: USA Setting: outpatient, single‐centre Author's name: Jeanna D. Blitz Institution: Department of Anesthesiology, New York University Langone Medical Centre, New York Email: jeanna.viola@nyumc.org Address: Department of Anesthesiology, New York University Langone Medical Centre, 550 1st Avenue RR 605, New York, NY 10016 Duration of study: NA Language: English Study's primary outcome: complete response Trial registry number: NCT00952133
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: quote: "were randomized". No further information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement
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	Unclear risk	Judgement comment: insufficient information on blinding ("double‐blind")
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: no missing outcome data
Selective reporting (reporting bias)	Unclear risk	Judgement comment: NCT00952133 (retrospective registration)
Other bias	Unclear risk	Judgement comment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender): no; (history of PONV/motion sickness, duration of anaesthesia, non‐smoker, perioperative opioids): unclear