Friedman 1980.

Methods	Randomised controlled trial 2‐arm parallel‐group design Trial duration: 8 weeks
Participants	34 participants with knee osteoarthritis were randomised 34 participants were reported at baseline Number of females: Not reported Mean age: 60.0 years
Interventions	Experimental intervention 20 mg triamcinolone hexacetonide, single intra‐articular injection Control intervention "Polysorbate, sorbitol solution, benzyl alcohol and water", single intra‐articular injection
Outcomes	Extracted pain outcome: Pain overall Maximum follow‐up: 8 weeks
Notes	Funding: Grant from the Eastern Pennsylvania Chapter of the Arthritis Foundation and by the Philadelphia Foundation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate random sequence of allocation was not clearly reported, so the risk of selection bias was unclear. Quote: "Half of the patients, selected according to a predetermined random schedule, were treated (...)."
Allocation concealment (selection bias)	Unclear risk	Method used to conceal the random sequence of allocation was not reported, so the risk of selection bias was unclear
Blinding of participants?	Low risk	Quote: "During the time of [the injection] (...), the physician and patient were positioned so that neither could see the nurse's face nor the material she injected. Thus, neither had any direct information concerning what was injected and, practically speaking, had no contact with the only person who knew"
Blinding of health care provider(s)	Low risk	Quote: "The physician‐experimenter performed the arthrocentesis (...) a nurse‐assistant entered the room and performed the injection through the intraarticular needle, and left the room. During the time of this taking place, the physician and patient were positioned so that neither could see the nurse's face nor the material she injected. Thus, neither had any direct information concerning what was injected and, practically speaking, had no contact with the only person who knew"
Intention‐to‐treat analysis performed? Pain	Low risk	All randomised participants included in the analysis. Quote: "All patients were seen 1 wk, 4 wk, 6 wk and 8 wk post‐injection except those whose pain scores at any subsequent evaluation were the same as their pre‐treatment scores; they were not seen further. It was assumed that their scores would no longer improve and they were counted as remaining at their pre‐treatment level throughout the experiment".
Intention‐to‐treat analysis performed? Function	Unclear risk	Not applicable, no function outcome reported