Zabihiyeganeh 2021.

Study characteristics
Methods	Design: parallel Duration:10 weeks Assessment: baseline and post‐intervention Country: Iran
Participants	Pain condition: fibromyalgia Population: women aged 18‐65 with fibromyalgia Minimum pain intensity: no Inclusion criteria Women aged 18‐65 with a definitive diagnosis of fibromyalgia Exclusion criteria Presence of co‐morbid conditions affecting the serum cytokine levels, including RA, OA, metabolic disorders, infection, etc. Severe psychiatric disorders; severe depression or anxiety (BDI score 30‐63) Total participants randomised: 128 Age in years (mean): 42.5 Gender: 128/128 were female Pain duration in years (mean): 3.9
Interventions	CBT n = 64 Psychological therapy Traditional face‐to‐face CBT was implemented based on the Beck and Ellis method, which was organised by Free 2007. The CBT was offered in twice‐weekly sessions over 10 weeks. Each session lasted 2 h. Duloxetine 60 mg n = 64 SNRI Fixed dose, forced titration
Outcomes	Pain intensity Quality of life AEs Withdrawal
Missing data methods	ITT with LOCF
Funding source	Non‐pharmaceutical: This study was funded by Iran University of Medical Sciences under the Grant code of 32415.
Conflicts of interest	The study authors declare that they have no confict of interest.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear ‐ state that was perfomed via a random number list, but also that participants were allocated depending upon order of referral: "the frst 64 random numbers were assigned to the CBT group, and the following 64 random numbers were assigned to the duloxetine group"
Allocation concealment (selection bias)	Unclear risk	Allocation methods unclear (see random sequence generation)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unable to be blinded due to nature of CBT intervention
Blinding of outcome assessment (detection bias) All outcomes	High risk	Self‐reported outcomes from unblinded participants
Incomplete outcome data (attrition bias) All outcomes	High risk	ITT with LOCF Attrition Total: 23/128 (18.0%) CBT: 12/64 (18.8%) Duloxetine 60 mg: 11/64 (17.2%)
Selective reporting (reporting bias)	Unclear risk	Prospectively registered protocol (https://en.irct.ir/trial/24406). Primary outcomes match but secondary outcomes (FIQ, Widespread Pain Index) not registered, no plan of analysis
Other bias	High risk	In the protocol they state a third group, a control group with no treatment, but this isn't mentioned anywhere in the paper.