Waldmann 1985.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 3 groups, monoprophylaxis
Participants	Baseline characteristics Placebo Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 20 Received treatment (n): NA Analysed (n): 20 Age (mean ± SD, median (IQR), median (range)): 24.6 ± 6.61 Weight (mean ± SD, median (IQR), median (range)): 58.5 ± 7.93 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (N₂O, halothane) Duration of anaesthesia or surgery (in min; as mean or median): 12.1 Use of perioperative opioids (if yes, which?): 0.05 mg fentanyl, pethidine Type of surgery: day‐care termination Domperidone Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 20 Received treatment (n): NA Analysed (n): 20 Age (mean ± SD, median (IQR), median (range)): 21.7 ± 4.4 Weight (mean ± SD, median (IQR), median (range)): 56.6 ± 8.73 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (N₂O, halothane) Duration of anaesthesia or surgery (in min; as mean or median): 16 Use of perioperative opioids (if yes, which?): 0.05 mg fentanyl, pethidine Type of surgery: day‐care termination Metoclopramide Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 20 Age (mean ± SD, median (IQR), median (range)): 23.2 ± 5.96 Weight (mean ± SD, median (IQR), median (range)): 60 ± 6.93 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (N₂O, halothane) Duration of anaesthesia or surgery (in min; as mean or median): 14.2 Use of perioperative opioids (if yes, which?): 0.05 mg fentanyl, pethidine Type of surgery: day‐care termination Included criteria: un‐premedicated women requiring day‐care terminations Excluded criteria: NA Pretreatment: baseline characteristics (age, weight): no; (ASA): unclear. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker, perioperative opioids): unclear
Interventions	Intervention characteristics Placebo Dose: saline Time point of administration: at induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): NA Domperidone Dose: 10 mg Time point of administration: at induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): NA Metoclopramide Dose: 10 mg Time point of administration: at induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): NA
Outcomes	PONV (0 to 24 hours) Outcome type: dichotomous outcome
Identification	Sponsorship source: NA Country: UK Setting: outpatient, single‐centre Author's name: C.S. Waldmann Institution: Anaesthetics Unit, London Hospital Medical College, Whitechapel, London, UK Email: NA Address: Anaesthetics Unit, London Hospital Medical College, Whitechapel, London El 1BB, UK Duration of study: NA Language: English Study's primary outcome: NA Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "a randomised double‐blind investigation was undertaken to assess the value of domperidone and metoclopramide as prophylactic anti‐emetics in unpremedicated patients undergoing general anaesthesia for therapeutic abortion on a day care basis" Quote: "sixty randomly numbered ampoules" Judgement comment: no further information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Quote: "sixty randomly numbered ampoules containing 2 ml normal saline, 2 ml (10 mg) metoclopramide, or 2 ml (10 mg) domperidone were disguised in the pharmacy and issued as the 'anti‐emetic' solution" Judgement comment: no statement on identical appearance of the ampoules provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "a randomised double‐blind investigation was undertaken to assess the value of domperidone and metoclopramide as prophylactic anti‐emetics in unpremedicated patients undergoing general anaesthesia for therapeutic abortion on a day care basis" Judgement comment: insufficient information on blinding ("double‐blind")
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "the incidence of nausea and vomiting in the recovery room was assessed by the recovery staff. On full recovery the patients received a questionnaire to take home, complete and return the following day" 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: no reference to a study protocol or trial registry number reported
Other bias	Unclear risk	Quote: "patients in each of the three drug groups had similar weight, age, length of pregnancy and duration of anaesthetic" Judgement comment: baseline characteristics (age, weight): no; (ASA): unclear. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker, perioperative opioids): unclear