Gabrail 2004.

Methods	Design: Randomised, double‐blind, two‐period cross‐over study. Prestudy open label stabilisation phase to establish fixed dosage that provided adequate analgesia for at least 2 consecutive days, required no more than 2 doses of rescue medication/day, and produced tolerable AEs ‐ used to calculate equianalgesic dose for study Duration: 2 x 7 ‐ 10 days + 3 ‐ 10‐day stabilisation phase Setting: outpatient
Participants	Moderate to severe pain secondary to cancer, requiring long‐term outpatient treatment with an opioid analgesic N = 44 (37 analysed for efficacy) M 21, F 23 Mean age 59 years (range 26 ‐ 81)
Interventions	Oxycodone CR 12‐hourly (8 am and 8 pm) Oxymorphone 12‐hourly (8 am and 8 pm) Dose adjustment allowed in first 3 days only Rescue medication: 15 mg oral morphine sulphate (IR) every 4‐6 hours as needed Other permitted medication not reported
Outcomes	PI: 11‐point NRS and BPI QoL: BPI (pain interference with 7 domains of quality of life: general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life) Global assessment of treatment: participant and physician Adverse events Karnovsky performance status
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	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	Study medication was "over encapsulated"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Study medication was "over encapsulated"
Incomplete adverse event outcome data‐ patient level	Low risk	> 90% of participants included
Selective reporting bias for adverse events	Low risk	All treatment related AEs reported
Size	High risk	< 50 participants per treatment arm