Creed 2003.

Study characteristics
Methods	Design: parallel Duration: 12 weeks Assessment: baseline, post‐intervention, follow‐up 1 year post‐intervention Country: UK
Participants	Pain condition: IBS Population: adults with IBS Minimum pain intensity: Inclusion criteria Aged 18‐65 Rome I criteria for IBS Severe abdominal pain, defined as > 59 on a VAS Exclusion criteria Psychotic disorder, severe personality disorder, active suicidal ideation Consumed > 50 units of alcohol per week Total participants randomised: 257 Age in years (mean): 43.3 Gender: 205/257 were female Pain duration in years (mean, SD): NR
Interventions	Psychotherapy n = 85 Psychodynamic interpersonal therapy 8 sessions of 3 months Paroxetine 20 mg/day n = 86 SSRI Fixed dose Usual treatment n = 86 Usual treatment ‐ patients continued to be seen either by their gastroenterologist and/or general practitioner, using whatever management was deemed appropriate throughout the 15 months of the study.
Outcomes	Pain intensity Physical function Mood Withdrawal
Missing data methods	ITT, data imputed using SOLAS (data imputation software)
Funding source	Non‐pharmaceutical ‐ Medical Research Council and UK North West Regional Health Authority Research and Development Directorate
Conflicts of interest	F Creed has consultancy links with Lilly. He has received payment for sitting on an advisory panel. All other authors declare that they have no competing interests.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was performed by a computer‐generated series of random numbers.
Allocation concealment (selection bias)	Unclear risk	When patients had been assessed and accepted into the trial, they were then allocated to a treatment group by the trial administrator using the next slot on the appropriate randomisation list.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and researchers unable to be blinded to due to nature of psychotherapy
Blinding of outcome assessment (detection bias) All outcomes	High risk	Self‐reported outcomes from unblinded participants
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unequal attrition. State ITT and data imputed by SOLAS ‐ but no explanation given Attrition Total: 69/257 (26.8%) Psychotherapy: 26/85 (30.6%) Paroxetine 20 mg: 32/86 (37.2%) Usual treatment: 11/86 (12.8%)
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration found
Other bias	Low risk	No other sources of bias were identified.