title: Cost-utility of a specific collaborative group intervention for patients with functional somatic syndromes.
abstract: Collaborative group intervention (CGI) in patients with functional somatic syndromes (FSS) has been shown to improve mental quality of life.
  
  
  
  To analyse incremental cost-utility of CGI compared to enhanced medical care in patients with FSS.
  
  
  
  An economic evaluation alongside a cluster-randomised controlled trial was performed. 35 general practitioners (GPs) recruited 300 FSS patients. Patients in the CGI arm were offered 10 group sessions within 3months and 2 booster sessions 6 and 12months after baseline. Costs were assessed via questionnaire. Quality adjusted life years (QALYs) were calculated using the SF-6D index, derived from the 36-item short-form health survey (SF-36). We calculated patients' net-monetary-benefit (NMB), estimated the treatment effect via regression, and generated cost-effectiveness acceptability curves.
  
  
  
  Using intention-to-treat analysis, total costs during the 12-month study period were 5777EUR in the intervention, and 6858EUR in the control group. Controlling for possible confounders, we found a small, but significant positive intervention effect on QALYs (+0.017; p=0.019) and an insignificant cost saving resulting from a cost-increase in the control group (-10.5%; p=0.278). NMB regression showed that the probability of CGI to be cost-effective was 69% for a willingness to pay (WTP) of 0EUR/QALY, increased to 92% for a WTP of 50,000EUR/QALY and reached the level of 95% at a WTP of 70,375EUR/QALY. Subgroup analyses yielded that CGI was only cost-effective in severe somatic symptom severity (PHQ-15≥15).
  
  
  
  CGI has a high probability to be a cost-effective treatment for FSS, in particular for patients with severe somatic symptom severity.
authors: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Germany. Electronic address: a.konnopka@uke.de.
authors: Alexander
authors: A
authors: Konnopka
authors: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Germany. Electronic address: h.koenig@uke.de.
authors: Hans-Helmut
authors: HH
authors: König
authors: Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany. Electronic address: claudia.kaufmann@med.uni-heidelberg.de.
authors: Claudia
authors: C
authors: Kaufmann
authors: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Germany. Electronic address: n.egger@uke.de.
authors: Nina
authors: N
authors: Egger
authors: Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany. Electronic address: Beate.wild@med.uni-heidelberg.de.
authors: Beate
authors: B
authors: Wild
authors: Department of General Practice and Health Services Research, University Hospital Heidelberg, Germany. Electronic address: joachim.szecsenyi@med.uni-heidelberg.de.
authors: Joachim
authors: J
authors: Szecsenyi
authors: Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany. Electronic address: wolfgang.herzog@med.uni-heidelberg.de.
authors: Wolfgang
authors: W
authors: Herzog
authors: Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany. Electronic address: dieter.schellberg@med.uni-heidelberg.de.
authors: Dieter
authors: D
authors: Schellberg
authors: Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany. Electronic address: Rainer.Schaefert@med.uni-heidelberg.de.
authors: Rainer
authors: R
authors: Schaefert
mesh_terms: D000328:Adult; D003299:Cooperative Behavior; D003362:Cost-Benefit Analysis / Q000379:methods*; D061345:Early Medical Intervention / Q000191:economics* / Q000379:methods; D005260:Female; D058005:General Practitioners / Q000191:economics*; D017048:Health Care Costs; D006801:Humans; D008297:Male; D000071896:Medically Unexplained Symptoms; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology; D019057:Quality-Adjusted Life Years; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
keywords: Collaborative care; Cost-effectiveness; Functional somatic syndromes