Yunus 1989.

Methods	Randomised, double‐blind, placebo‐controlled, parallel‐group Single centre (ambulatory rheumatology clinic), USA Duration screening and washout not reported, 3 weeks parallel double‐blind group phase followed by 3 weeks open trial Analyses based on at least 3 weeks in study, and separately for ITT population. No imputation described and some analyses based on 43/46 participants Analgesics and NSAIDs discontinued 1 week before enrolment No stated minimum pain intensity, though 44/46 had moderate or severe pain
Participants	Ibuprofen 600 mg four times a day: N = 22; 95% female; race not reported; mean age 38.6 (SD 10.5) years; pain duration 7.3 (SD 6.5 years); pain baseline (1‐4 scale) 2.7 (SD 0.6) Placebo: N = 24; 96% female; race not reported; mean age 39.1 (SD 7.5) years; pain duration 7.7 (SD 7.1 years); pain baseline (1‐4 scale) 2.9 (SD 0.8) Inclusion criteria:Yunus 1981 Exclusion criteria: No underlying condition to explain fibromyalgia symptoms, though this was not a specific exclusion criterion
Interventions	Ibuprofen 600 mg four times a day Placebo
Outcomes	Pain: Average pain severity (NRS 0‐10) last 24 hours; pain relief of 50% or more reported; pain relief 30% and more not reported PGIC much or very much improved: PGIC (1‐7) reported Fatigue: FIQ single item (VAS 0‐10): not reported Sleep: not assessed Quality of life: FIQ total score (0‐80); not reported Adverse events (AEs): physical examination, electrocardiograms (ECGs), and laboratory analysis. Further details of assessment of adverse symptoms not reported Depression: BDI ‐II total score (NRS 0‐63) Anxiety: Beck Anxiety Inventory total score (NRS 0‐63); not reported Disability: FIQ single item (VAS 0‐10): not reported Cognitive disturbances: not assessed Sexual function: not assessed Tenderness: mean tender point threshold (kg/cm²)
Notes	Oxford Quality Score R = 1 DB = 2 W = 1 Total = 4/5 No conflicts of interest reported Funding source ‐ Wyeth
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	Low risk	Matched placebo
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	4/46 withdrew by week 3
Selective reporting (reporting bias)	Low risk	All important outcomes reported
Group similarity at baseline	Low risk	Similar at baseline
Sample size bias	High risk	Fewer than 50 participants per treatment arm

ACR: American College of Rheumatology; BDI: Beck Depression Inventory; BPI: British Pain Inventory; DB: double‐blind; FIQ: Fibromyalgia Impact Questionnaire; FM: fibromyalgia; HADS: Hospital Anxietry and Depression Scale; HAQ: Health Assessment Questionnaire; HAS: Health Assessment Scale; HRDS: Hamilton Depression Rating Scale; HARS: Hamilton Anxiety Rating Scale; ITT: Intention to treat; LOCF: last observation carried forward; N: number of participants in study; n: number of participants in treatment arm; NRS: Numerical rating scale; PGIC: Patient Global Impression of Change; R: randomised; SD: standard deviation; SEM: Standard error of the mean; VAS: visual analogue scale; W: withdrawals.