Markenson 2005.

Methods	Randomised controlled trial 2‐arm parallel group design Trial duration: 13 weeks Multicentre trial with 9 centres Power calculation reported
Participants	Participants with moderate‐to‐severe pain while taking NSAIDs/paracetamol, with contraindications to NSAID therapy or with previous oral opioid therapy were eligible 109 participants were randomised 107 participants with osteoarthritis were reported at baseline Affected joints: 33 knees, 19 hips, and 57 other joints Number of females: 78 of 107 (73%) Mean age: 63 years
Interventions	Experimental intervention Oral oxycodone (OxyContin), 10 mg twice daily Control intervention Placebo, twice daily Treatment duration: 13 weeks Analgesics other than study drugs allowed and intake assessed, but it was unclear whether intake was similar
Outcomes	Extracted pain outcome: global pain after 13 weeks Extracted function outcome: WOMAC global scale after 13 weeks
Notes	Sponsor: Purdue Pharma
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The computer‐generated randomization code and study drug bottles labeled with randomization numbers were supplied by the sponsor"
Allocation concealment (selection bias)	Low risk	Quote: "The computer‐generated randomization code and study drug bottles labeled with randomization numbers were supplied by the sponsor"
Described as double‐blind?	Low risk	Quote: "This was a double blind, randomized, placebo‐controlled, parallel‐group study"
Blinding of patients?	Low risk	Because the study used indistinguishable interventions, we considered participants to be blinded Quote: "Patients who met the entry criteria were randomly assigned in double blind fashion to receive either 10‐mg tablets of CR oxycodone or matching placebo every 12 hours"
Blinding of physicians?	Low risk	Because coded labelled bottles were provided by sponsor and drug tables were matching the placebo tablets, physicians were considered blinded as well
Blinding of outcome assessors?	Low risk	Because participants were blinded and outcomes were participant‐reported, the risk of detection bias was considered low
Interventions reported as indistinguishable?	Low risk	Quote: "Patients who met the entry criteria were randomly assigned in double blind fashion to receive either 10‐mg tablets of CR [controlled release] oxycodone or matching placebo every 12 hours"
Double‐dummy technique used?	High risk	No double‐dummy technique used
Intention‐to‐treat analysis performed? Pain	High risk	2 randomised participants who withdrew before receiving treatment were excluded from the analyses
Intention‐to‐treat analysis performed? Function	High risk	2 randomised participants who withdrew before receiving treatment were excluded from the analyses