Chappell 2008.

Study characteristics
Methods	Design: parallel Duration: 27 weeks Assessment: baseline and post‐intervention Country: USA, Germany, Spain, Sweden, UK
Participants	Pain condition: fibromyalgia Population: adults with fibromyalgia Minimum pain intensity: none Inclusion criteria Adults with fibromyalgia diagnosed as per the ACR criteria With or without MDD Exclusion criteria Severe physical health comorbidity Total participants randomised: 330 Age in years (mean, SD): 50.5 (10.7) Gender: 308/330 were female Pain duration in years (mean, SD): NR
Interventions	Placebo n = 168 Inert Duloxetine n = 162 SNRI Blind forced titration to fixed doses dependent upon efficacy for pain relief Mean dose at end of trial was 113.4 mg/day
Outcomes	Pain intensity Quality of life Mood Physical function Moderate pain relief Substantial pain relief PGIC AEs Withdrawal
Missing data methods	ITT with LOCF
Funding source	Pharamaceutical ‐ Eli Lilly and Boehringer Ingelheim GmbH
Conflicts of interest	Drs Chappell, Detke, and D'Souza are employees and stockholders of Eli Lilly and Company. Dr Wiltse is a former employee of Eli Lilly and Company. Dr Spaeth is a consultant to Allergan, Eli Lilly, Jazz, and Pierre Fabre Medicament, and is on the speaker bureaus of Eli Lilly and Pierre Fabre Medicament. Dr Bradley is a consultant for Eli Lilly, Pfizer, and Forest; has received grant/research support from the National Institutes of Health, the Agency for Healthcare Research and Quality, Eli Lilly, Pfizer, and the American Fibromyalgia Syndrome Association; has received honoraria from Eli Lilly, Pfizer, Forest, and the Society for Women's Health Research; is a member of the speaker/advisory board for Pfizer; and has received royalties from UpToDate Rheumatology.
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 within each study centre, stratified by MDD status
Allocation concealment (selection bias)	Unclear risk	Allocation procedure not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, identical appearance tablets
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	Significant difference in participants withdrawing due to lack of efficacy (higher in placebo). Uses ITT with LOCF Attrition Total: 126/330 (38.2%) Placebo: 65/168 (38.7%) Duloxetine 60‐120 mg: 61/162 (37.7%)
Selective reporting (reporting bias)	Low risk	Outcomes match those listed in trial registration record
Other bias	Low risk	No other sources of bias were identified.