Brewer 1982.

Methods	Allocation: randomised Blinding: double‐blind Controlled: active comparator Centre: multicentre Arm: 2 arms, parallel groups
Participants	Inclusion criteria: children with juvenile rheumatoid arthritis Exclusion criteria: unstated Baseline characteristics N = 99 Age: range unstated; mean age 8.5 years Gender: male (23); female (76) Number randomised: fenoprofen (49); aspirin (50) Number completed: fenoprofen (47); aspirin (40) Setting and location: multicentre, location unstated
Interventions	Intervention group (N = 49): aspirin 1500 mg/m2/day increased to 3000 mg/m2/day, maximum 5450 mg/day Control group (N = 50): fenoprofen 900 mg/m2/day increased to 1800 mg/m2/day, maximum 3200 mg/day Study duration: 12 weeks
Outcomes	Primary outcomes Unstated Secondary outcomes Adverse reactions
Notes	Sources of funding: unstated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "99 patients were randomized into the study" Comment: No information regarding method of randomisation
Allocation concealment (selection bias)	Unclear risk	Quote: Insufficient information
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "capsules containing either fenoprofen or ASA were white opaque size #2 for the 0.5 to 0.75m2 groups, and white opaque size #1 for the 0.76m2 and over groups. Therefore it was impossible to determine which drug the subjects were receiving by observing capsule size, colour, or administration regimen"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: Insufficient information
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: All participants were accounted for. Lost to follow‐up and withdrawals explained. However, authors do not report whether there were significant differences between completers and non‐completers.
Selective reporting (reporting bias)	Unclear risk	Quote: "all investigators used an identical protocol and case report forms" Comment: No outcomes were not set out in the methods. Unable to locate protocol.
Size	High risk	Comment: Total participants = 99 (< 50 per treatment arm)
Other bias	Low risk	Comment: No other potential sources of bias found.