title: [At what time is a reduction of medical under- or overtreatment sensible? Treatment of acute depression as an example].
abstract: OBJECTIVE
  1) To portray the mathematical relationship between the size of an underuse or overuse problem caused by non-compliance of health professionals and the cost-effectiveness of a quality improvement program; 2) to demonstrate the applicability of the models to a real-world problem (underuse and overuse in the treatment of major depression) and to stress the importance of the costs of a quality improvement program using this example.
  
  
  METHODS
  Mathematical formulation of the relationship between the costs of a quality improvement program and the degree of underuse and overuse.
  
  
  RESULTS
  The example of reducing underuse in the treatment of major depression shows that an intervention with a favorable cost-effectiveness ratio may be economically unattractive if a quality improvement program incurs high costs secondary to a small quality deficit. The application example also shows that reducing treatment overuse is inefficient if overuse is small and hence the costs of a quality improvement program are higher than the costs of overuse.
  
  
  CONCLUSIONS
  The explicit consideration of the size of an underuse or overuse problem in the cost-effectiveness ratio of a quality improvement program may contribute to a more efficient use of health care resources.
authors.affiliation: Institut für Gesundheitsökonomie und Klinische Epidemiologie, Universität zu Köln, Köln. afschin.gandjour@medizin.uni-koeln.de
authors.forename: Afschin
authors.initials: A
authors.lastname: Gandjour
authors.forename: Karl Wilhelm
authors.initials: KW
authors.lastname: Lauterbach
mesh_terms: D000639:Amitriptyline / Q000191:economics / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000191:economics / Q000627:therapeutic use; D015283:Citalopram / Q000191:economics / Q000627:therapeutic use; D003362:Cost-Benefit Analysis / Q000706:statistics & numerical data; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy / Q000191:economics*; D016527:Drug Costs / Q000706:statistics & numerical data; D005858:Germany; D019983:Guideline Adherence / Q000191:economics; D006300:Health Services Misuse / Q000191:economics*; D006801:Humans; D018803:Models, Economic; D015233:Models, Statistical; D009313:National Health Programs / Q000191:economics*; D011785:Quality Assurance, Health Care / Q000191:economics; D016312:Treatment Refusal
chemical_list: D000928:Antidepressive Agents; D015283:Citalopram; D000639:Amitriptyline