title: Cost-effectiveness of collaborative care for the treatment of depressive disorders in primary care: a systematic review.
abstract: BACKGROUND
  For the treatment of depressive disorders, the framework of collaborative care has been recommended, which showed improved outcomes in the primary care sector. Yet, an earlier literature review did not find sufficient evidence to draw robust conclusions on the cost-effectiveness of collaborative care.
  
  
  OBJECTIVE
  To systematically review studies on the cost-effectiveness of collaborative care, compared with usual care for the treatment of patients with depressive disorders in primary care.
  
  
  METHODS
  A systematic literature search in major databases was conducted. Risk of bias was assessed using the Cochrane Collaboration's tool. Methodological quality of the articles was assessed using the Consensus on Health Economic Criteria (CHEC) list. To ensure comparability across studies, cost data were inflated to the year 2012 using country-specific gross domestic product inflation rates, and were adjusted to international dollars using purchasing power parities (PPP).
  
  
  RESULTS
  In total, 19 cost-effectiveness analyses were reviewed. The included studies had sample sizes between n = 65 to n = 1,801, and time horizons between six to 24 months. Between 42% and 89% of the CHEC quality criteria were fulfilled, and in only one study no risk of bias was identified. A societal perspective was used by five studies. Incremental costs per depression-free day ranged from dominance to US$PPP 64.89, and incremental costs per QALY from dominance to US$PPP 874,562.
  
  
  CONCLUSIONS
  Despite our review improved the comparability of study results, cost-effectiveness of collaborative care compared with usual care for the treatment of patients with depressive disorders in primary care is ambiguous depending on willingness to pay. A still considerable uncertainty, due to inconsistent methodological quality and results among included studies, suggests further cost-effectiveness analyses using QALYs as effect measures and a time horizon of at least 1 year.
authors.affiliation: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Grochtdreis
authors.affiliation: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Brettschneider
authors.affiliation: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Wegener
authors.affiliation: Clinical Psychology and Psychotherapy Research, Institute of Psychology, University of Zurich, Zurich, Switzerland.
authors.forename: Birgit
authors.initials: B
authors.lastname: Watzke
authors.affiliation: Institute of Social Medicine, Occupational Health and Public Health, University of Leipzig, Leipzig, Germany.
authors.forename: Steffi
authors.initials: S
authors.lastname: Riedel-Heller
authors.affiliation: Department of Medical Psychology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Härter
authors.affiliation: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Hans-Helmut
authors.initials: HH
authors.lastname: König
mesh_terms: D003299:Cooperative Behavior; D003362:Cost-Benefit Analysis; D003866:Depressive Disorder / Q000523:psychology / Q000628:therapy*; D006801:Humans; D011320:Primary Health Care; D019057:Quality-Adjusted Life Years