Johansson 1982.

Study characteristics
Methods	Randomised, double‐blind, 2‐period cross‐over study
Participants	27 people aged 18‐70 years Tumour types: cervical cancer (2 people), cancer of fallopian tubes (2 people), ovarian cancer (13 people), testicular cancer (2 people), head and neck cancer (1 person), bronchus cancer (1 person), histiocytoma (1 person), fibrosarcoma (1 person), oligodendroma (1 person), lymphoma (2 people) Chemotherapy regimens: doxorubicin 40 mg/m2, cyclophosphamide 500 mg/m2 and cisplatinum 50 mg/m2 (11 people) in combination with vinblastine, vincristine or ftorafur (tegfur‐uracil). Cyclophosphamide 750‐1000 mg/m2 and cisplatinum 75 mg/m2 when given as sole agents Chemotherapy emetogenicity: high
Interventions	Nabilone 2 mg twice daily x 4 days orally, n = 27 Prochlorperazine 10 mg twice daily x 4 days orally, n = 27
Outcomes	Episodes of nausea and vomiting assessed daily and reported for follow‐up at end of anti‐emetic therapy; withdrawal due to lack of efficacy; withdrawal due to hypotension, vertigo and headache; participant preference; episodes of drowsiness, dizziness, depression, hypotension
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	18/27 (67%) participants received nabilone, 18/27 (67%) participants received prochlorperazine
Selective reporting (reporting bias)	Low risk	Data reported for primary outcome
Other bias	Unclear risk	Assumed washout period sufficient. Unclear if paired analysis was performed. Unclear if groups were balanced at baseline
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Reported as "double‐blind"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding assumed as study reported as "double‐blind"