Arnold 2004.

Study characteristics
Methods	Design: parallel Duration: 12 weeks Assessment: baseline and post‐intervention (12 weeks) Country: USA
Participants	Pain condition: fibromyalgia Population: adults with fibromyalgia with and without MDD Minimum pain intensity: ≥ 4 out of 10 Inclusion criteria  ≥ 8 years of age and met the ACR criteria for fibromyalgia Score ≥ 4 on the pain intensity item of the Fibromyalgia Impact Questionnaire (with 10 indicating very severe pain) at visits 1 and 2 Have an educational level and degree of understanding that allowed them to communicate intelligibly. Exclusion criteria Pain from traumatic injury or structural or regional rheumatic disease; RA, inflammatory arthritis, or autoimmune disease; unstable medical or psychiatric illness; current dysthymia, which is more treatment‐resistant than major depression, or primary psychiatric disorder other than MDD; substance abuse in the last year; history of psychosis; pregnancy or breastfeeding; unacceptable contraception in those of childbearing potential; or involvement in disability reviews that might compromise treatment response Use of an investigational drug within 30 days; prior participation in a study of duloxetine; severe allergic reactions to multiple medications; intolerance to 3 psychoactive drugs or 1 SSRI; and failure to respond to 2 adequate regimens of 2 different classes of antidepressants for depression or fibromyalgia Total participants randomised: 207 Age in years (mean, SD):  Gender: 184/200 were female Pain duration: NR
Interventions	Duloxetine SNRI Fixed dose of 120 mg/day, 2 x 60 mg doses Forced titration from 20 mg/day to 120 mg/day over 2  weeks Placebo Inert Identical dosing strategy to duloxetine
Outcomes	Pain intensity Quality of life Physical function Mood PGIC AEs Withdrawal
Missing data methods	Mixed‐effects model and LOCF
Funding source	Pharmaceutical ‐ Eli Lilly
Conflicts of interest	Drs Crofford and Arnold have received consulting fees or honoraria in the last 2 years from Eli Lilly and Company (DrCrawford USD 10,000, Dr Arnold USD 10,000). In addition to the authors employed by Eli Lilly and Company listed above, Dr Goldstein's wife is employed by Eli Lilly and Company
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Assignment to treatment groups was determined by a computer‐generated random sequence.
Allocation concealment (selection bias)	Low risk	Participants were allocated using an interactive voice response system.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Matched appearance and dosing schedule
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes from blinded participants
Incomplete outcome data (attrition bias) All outcomes	High risk	High attrition, unequal reasons for dropout, used LOCF Attrition: Total: 83/207 (40.1%) Placebo: 37/103 (35.9%) Duloxetine 120 mg: 46/104 (44.2%)
Selective reporting (reporting bias)	Unclear risk	Trial registration was retrospective.
Other bias	Low risk	No other sources of bias were identified.