Goldenberg 1986.

Methods	Randomised, double‐blind, placebo‐controlled, parallel‐group Probably single centre in USA Duration of screening and washout not reported, 6‐week parallel group phase No obvious imputation for withdrawals if participants completed 2 visits No NSAID or other drug for 3 days before initial visit Minimum pain intensity 4/10 or higher
Participants	Naproxen: N = 19 Placebo: N = 19 No demographic information for separate groups. Overall mean age 44 years (range 21‐69), 95% women, 87% white Pain baseline (extracted from figure): 7.6 Mean years of chronic pain 3.5 (0.5‐20) years Inclusion criteria: modified Yunus 1981 Exclusion criteria: history of peptic ulcer disease or cardiac arrhythmias, or if they were taking medications that could not be stopped
Interventions	Naproxen 500 mg twice a day Placebo
Outcomes	Pain: 0‐10 cm PGIC much or very much improved: 0‐10 cm Fatigue: 0‐10 cm Sleep problems: 0‐10 cm Adverse events (AEs): no information provided Health‐related quality of life: not assessed Psychological distress: not assessed
Notes	Oxford Quality Score R = 1 DB = 1 W = 1 Total = 3/5 No conflicts of interest reported Funding source ‐ Arthritis Foundation, and Syntex
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details reported
Allocation concealment (selection bias)	Unclear risk	No details reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No details reported, though both "blinded"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participant reported, or all participants evaluated in a blinded manner by one assessor
Incomplete outcome data (attrition bias) All outcomes	Low risk	Over 90% of participants reported data, and no imputation mentioned
Selective reporting (reporting bias)	Low risk	All important outcomes reported
Group similarity at baseline	Unclear risk	No information
Sample size bias	High risk	Fewer than 50 participants per treatment arm