Guo‐Zhu 1997.

Methods	Design: randomised, open label, parallel group study comparing 2 doses of Mm/r capsules with 2 doses of Mm/r tablets (4 groups in total). No dose titration; lower dose given to those who had not used, or rarely used, opiates previously Duration of treatment: 7 days Setting: hospital
Participants	Terminal cancer and moderate to severe pain N = 120 M 72, F 48 Mean age approximately 55 years
Interventions	Mm/r granules 20 mg or 30 mg 12‐hourly Mm/r tablets 20 mg or 30 mg 12‐hourly Rescue medication not mentioned Use of antidepressants, non opioid drugs, acupuncture and TCM prohibited
Outcomes	PI: 10‐point NRS PR: 5‐point categorical scale Adverse events
Notes	Oxford Quality Score: R = 1, DB = 0, W = 0. Total = 1/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomly divided". Method used to generate sequence not clearly stated
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open study
Blinding of outcome assessment (detection bias) All outcomes	High risk	Open study
Incomplete adverse event outcome data‐ patient level	Low risk	> 90% of participants included
Selective reporting bias for adverse events	Low risk	All AEs appear to be included
Size	High risk	< 50 participants per treatment arm