Chan 1987.

Methods	RCT Cross‐over
Participants	Any paediatric malignancy, but patients in whom a chemotherapy cycle was previously shown to cause moderate to severe drug‐induced nausea and vomiting No participants received cisplatin. Participants had not previously been treated with either nabilone or prochlorperazine. 30 participants, median age 11.8 years (3.5 to 17.8 years), gender not specified
Interventions	Nabilone orally (1 mg capsules) starting 8 to 12 hours prior to chemotherapy and repeated 2 or 3 times a day according to dosage schedule Original schedule: 18 to 27 kg 1 mg BD 27.1 to 36 kg 1 mg TDS > 36 kg 2 mg BD Modified schedule: < 18 kg 0.5 mg BD 18 to 30 kg 1 mg BD > 30 kg 1 mg TDS Prochlorperazine orally (capsules) starting 8 to 12 hours prior to chemotherapy and repeated 2 or 3 times a day according to dosage schedule Original schedule: 18 to 27 kg 5 mg BD 27.1 to 36 kg 5 mg TDS > 36 kg 10 mg BD Modified schedule: < 18 kg 2.5 mg BD 18 to 30 kg 5 mg BD > 30 kg 5 mg TDS
Outcomes	Vomiting was recorded as the total number of episodes of vomiting or retching
Notes	Study supported by a grant from Eli Lilly (company supplying nabilone)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding (performance bias and detection bias) Acute nausea	High risk	Not reported
Blinding (performance bias and detection bias) Acute vomiting	Unclear risk	Medical staff and participants/parents not aware of drug allocation, but nabilone has frequent, significant, and immediately identifiable side effects Blinding of care provider: unclear Blinding of participant: unclear Blinding of outcome assessors: unclear
Blinding (performance bias and detection bias) Other outcomes	High risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	10 withdrawals, all included in toxicity assessments. 4 change of chemotherapy after cycle 1; 2 unable to cope with diagnosis and treatment; 2 received other antiemetics during study period; 2 cycle 2 of chemotherapy deferred because of severe dizziness/drowsiness after a single 2 mg dose of nabilone prior to treatment
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Low risk	No other risk of bias noted