Schaefert 2013.

Methods	Study design: cluster‐randomised controlled trial
Participants	Diagnosis: MUS Method of diagnosis: participants were eligible in case of: 1. persistent (> 6 months) bodily complaints without sufficient explanatory peripheral organ pathology (according to GP), 2. MUS as the main treatment issue, 3. PHQ‐15 score of ≥ 5, 4. relevant health anxiety on the WI‐7 (score ≥ 4), or a combination of these Exclusion criteria: age < 18 or > 70 years, living further than 20 miles away from the respective practice; ongoing psychotherapy; substance abuse; severe psychiatric disorder (e.g. major depression, psychosis, dementia); severe organic disease; inability to complete the questionnaire, or ongoing litigation due to disability, pension or compensation for personal suffering Total number randomised: 328 Age: for intervention group, M = 50.8 (SD = 12.0); for control group, M = 46.6 (SD = 12.9) Sex: for intervention group 75.3% women (n = 128), 24.7% men (n = 42); for control group 74.6% women (n = 100), 25.6% men (n = 34) Severity of symptoms at baseline: somatic symptom severity according to PHQ‐15‐score: LOW (0‐9): for intervention group 28.2% (n = 48) for control group 30.6% (n = 41) MEDIUM (10‐14): for intervention group 38.2% (n = 65) for control group 35.8% (n = 48) HIGH (15‐30): for intervention group 33.5% (n = 57) for control group 33.6% (n = 45) Duration of symptoms at baseline: for intervention group M = 6.74 years (SD = 5.4), for control group M = 5.00 years (SD = 4.6) Setting: participants were recruited and treated by GPs in primary care Location: Heidelberg area, Germany Number of treatment centres: 35 GPs (from 34 practices) Co‐morbidities: Depressive symptoms: for intervention group 33.5% (n = 57); for control group 43.3% (n = 58) Generalised anxiety: for intervention group 16.6% (n = 28); for control group 21.8% (n = 29) Panic disorder: for intervention group 21.8% (n = 29); for control group 17.3% (n = 23) Musculoskeletal system disorders: for intervention group 45%; for control group 51% Hypertension: for intervention group 39%; for control group 39% Endocrine/alimentary/metabolic disorders: for intervention group 34%; for control group 34% Gastrointestinal system disorders: for intervention group 25%; for control group 29% Adjunctive therapy: none reported Adjunctive medication: none reported
Interventions	Participants were randomly assigned to either 1. GP training in diagnosis and management of MUPS and group leading (GP level) + an interpersonal approach of psychodynamically based therapy (participant level) (n = 183) Duration: GP level: 4 training sessions, in total 15.5 hours (diagnosis + management of MUPS) + 3 sessions, in total 12 hours (group leading) participant level: 10 weekly sessions of 90 minutes + 2 booster sessions 3 and 9 months later Treatment protocol: GP level: guideline based curriculum for training of GPs in diagnosis and management of MUPS, consisting of lectures, discussions and role plays (Schaefert 2013, ref 42 for details) + GP training in group leading (methodology not described) Participant level: manualised group intervention consisting of an interpersonal approach of psychodynamically based therapy, with embedded cognitive behavioural elements (Schaefert 2013, table 1 and ref 43 for details) Therapist: GP level: the investigators; participant level: GP + 1‐3 psychosomatic specialists (with ≥ 3 years of training in psychosomatic therapy) 2.GP training in diagnosis and management of MUPS (n = 145) Duration: GP level: 4 training sessions, in total 15.5 hours (diagnosis + management of MUPS) Treatment protocol: guideline based curriculum for training of GPs in diagnosis and management of MUPS, consisting of lectures, discussions and role plays (Schaefert 2013, ref 42 for details) Therapist: GP level: the investigators
Outcomes	Time points for assessment: baseline and 6 months, 12 months after baseline Primary outcome: Quality of life (SF‐36, PCS and MCS) Secondary outcome: Somatic symptom severity (PHQ‐15) Depression (PHQ‐9) Anxiety and panic (PHQ anxiety and panic, only at baseline) Stress (PHQ stress) Health anxiety (WI) Healthcare utilisation (GP documentation and self report)
Notes	Date of study: participant recruitment started in November 2007 in both groups and ended in September 2008 in the intervention group and in December 2009 in the control group, follow‐up continued until the end of 2010 Funding source: German Federal Ministry of Education and Research Declarations of interest among the primary researchers: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	GPs were unit of randomisation, randomisation was performed in a data and co‐ordinating centre
Allocation concealment (selection bias)	Low risk	Blinded randomisation was performed by a statistician under independent management. The GPs were informed by a research assistant
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of participants and personnel possible
Blinding of outcome assessment (detection bias) All outcomes	High risk	Participants were not blinded, and most outcomes were participant reported
Incomplete outcome data (attrition bias) All outcomes	High risk	Incomplete data in intervention group at 6 months 20.8%, at 12 months 21.9% Incomplete data in control group at 6 months 31.8%, at 12 months 25.6%
Selective reporting (reporting bias)	Low risk	All intended outcomes reported
Treatment fidelity	Low risk	The participating GPs were trained with a guideline‐based curriculum in the diagnosis and management of MUS (Schaefert 2013, ref 41, 42)
Researcher allegiance	Unclear risk	Some of the authors were also providing the intervention
Other bias	Low risk	No other sources of bias