Castel 2009.

Methods	Study setting: Europe (Spain). SIngle centre, recruitment in university pain clinic, outpatient based Study design: Parallel Duration therapy: 12 weeks Follow‐up: None   Analysis: T‐tests and Chi2 analysis to compare treatment conditions in demographic and pre‐treatment outcome variables, paired t‐tests to evaluate changes in each condition treatment, univariate analyses to compare between treatments, percentage of patients that experienced a significant change in pain intensity was evaluated, cut‐off of 30% accepted as indicator of clinically important improvement, evaluation of Pearson correlation between hypnotisability and pre‐post‐treatment differences
Participants	Patients: Treatment Group: 18 patients, 94% female, race not reported, mean age 43.0 years; pain duration 10.2 (10.7) years Control Group: 12 patients, 86% female, race not reported, mean age 49.6 years; pain duration 7.1 (5.6) years Inclusion: ACR 1990 criteria for FM, age between 18 years and less than 60 years, having a minimum of 6 months history of chronic pain, having at least 6 years of education Exclusion: One or more additional severe chronic medical pain conditions, significant suicidal ideation, severe psychopathology (e. g. psychosis), moderate to severe cognitive impairment, presence of pending litigation
Interventions	Treatment Group: CBT, group: didactic presentation of information about FMS and theory of pain perception, relaxation training, cognitive restructuring, assertiveness training, behavioral goal setting, problem solving, training in outcome generalization, maintenance of gains, audio CD of a relaxation exercise to listen to at home (1.5h/week), total: 18h Control Group: TAU: Pharmacological treatment including analgesics, antidepressants, sedatives, myorelaxants Comedication allowed: Standard medication management Other Cotherapies: Not reported
Outcomes	Primary Outcomes Self reported pain: Numeric Pain Rating Scale (NPRS) 0‐10 NR Self reported negative mood: FIQ depression 0‐10; Data provided on request Self reported disability: FIQ physical impairment 0‐10; Data provided on request Acceptability: Total dropout rate Secondary Outcomes Self reported self efficacy pain: Not assessed Self reported fatigue: FIQ fatigue 0‐10; data provided on request Self reported sleep problems: Not assessed Self reported disease‐specific health‐related quality of life: FIQ total 0‐100
Notes	1. Study arm CBT plus hypnosis (not used for comparison) 2.Reasons for dropout: Not reported 3. Attendance rates: Not reported 4. Responder analysis: None 5. Funding sources and declaration of interest of the primary researchers: No details reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No detailed information
Allocation concealment (selection bias)	Unclear risk	No detailed information
Incomplete outcome data (attrition bias) All outcomes	High risk	No Intention‐to‐treat analysis
Selective reporting (reporting bias)	Low risk	All outcomes reported or provided on request
Blinding of outcome assessor	Unclear risk	No detailed information