Parris 1998.

Methods	Design: multicentre, randomised, double‐blind (double dummy), parallel group study Duration: 5 days Setting: Not stated
Participants	Cancer‐related pain requiring 6 to 12 tablets or capsules per day of fixed‐combination analgesics for acceptable control. Most common cancer diagnoses were breast, gastrointestinal, lung, and gynaecological N = 103 50% female Mean age 57 years (range 31‐80)
Interventions	Oxycodone CR 30 mg 12‐hourly, n = 52 Oxycodone IR 15 mg x 4 daily, n = 51 Stable doses of non opioid analgesics or analgesic adjuvants allowed after protocol amendment Rescue medication: participants needing titration of analgesic or supplemental medication were required to discontinue from the study
Outcomes	PI: 4‐point categorical scale (0 ‐ 3) x 4 daily Acceptability of therapy: 5‐point categorical scale (1 ‐ 5), x 2 daily Adverse events, daily
Notes	Oxford Quality Score: R = 1, DB = 2, W = 1. Total = 4/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomized". 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	Low risk	Double dummy method
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Double dummy method
Incomplete adverse event outcome data‐ patient level	Low risk	>90% participants included
Selective reporting bias for adverse events	High risk	Selective reporting of >5% of patients with an AE
Size	Unclear risk	50 ‐ 199 participants per treatment arm