De effectiviteit en kosteneffectiviteit van psychosomatische therapie voor patiënten met Somatisch Onvoldoende verklaarde Lichamelijke Klachten die hun huisarts veelvuldig bezoeken; het CORPUS onderzoek

The aim of this study is to evaluate the costs and effects of psychosomatic therapy, delivered by physical and exercise therapists, compared with usual care for patients who frequently attend their general practitioner (GP) with medically unexplained symptoms.

The study consists of two parts. Part 1; Effect and economic evaluation with a randomized cost-effectiveness trial in primary care. 160 patients (18-80) with medically unexplained symptoms will be randomized into intervention (n=80; psychosomatic therapy in addition to usual care) or control condition (n= 80) usual care alone). All patients will be followed for one year and will be asked to complete questionnaires at baseline and at 4 and 12 months follow-up.

Part 2; Process evaluation with a quantitative and qualitative (sub)study with both therapists(n=24)  and participating patients (n=15-30) in the intervention group.

Intervention: Psychosomatic therapy (6-12 sessions of 30-45 minutes) is a multi-component, stepped-care and tailor-made approach and includes the following modules: (1) psycho-education, (2) relaxation therapy and mindfulness, (3) cognitive behavioural approaches and (4) activating therapy. The aim of the intervention is empowerment of the patients to regain control over their own health.

The primary clinical outcome is patients’ level of specific functioning and disability measured with the patient-specific functional scale (PSFS).
The primary outcome measure for the economic evaluation is quality of life assessed by the SF-6D. Health care costs, medical consumption and work limitations will be assessed with the Medical Consumption Questionnaire (iMCQ) and work limitations with the Productivity Cost Questionnaire (iPCQ).