Mizuguchi 1990.

Methods	Design: multicentre, randomised, single blind (double dummy), cross‐over study Duration: 2 x 3 days. No washout Setting: not clear, probably inpatient
Participants	Cancer pain N = 46 Mean age 58 years (±12)
Interventions	Morphine HCL 20 mg suppository x 3 daily MS Contin 3 x 10 mg tablets x 2 daily Previoius medication continued
Outcomes	PI: 4‐point categorical scale PR: 6‐point categorical scale Sleep Adverse events Global assessment
Notes	Oxford Quality Score: R = 2, DB = 0, W = 1. Total = 3/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomisation by code". 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	Unclear risk	"matching placebos were prepared" but states single blind
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"matching placebos were prepared"
Incomplete adverse event outcome data‐ patient level	Unclear risk	Unable to determine
Selective reporting bias for adverse events	High risk	Selective reporting
Size	High risk	< 50 participants per treatment arm