title: Systematic review of models used in economic analyses in moderate-to-severe asthma and COPD.
abstract: BACKGROUND
  Respiratory diseases exert a substantial burden on society, with newer drugs increasingly adding to the burden. Economic models are often used, but seldom reviewed.
  
  
  OBJECTIVE
  To summarize economic models used in economic analyses of drugs treating moderate-to-severe/very severe asthma or chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  This study searched Medline and Embase from inception to the end of February 2015 for cost-effectiveness/utility analyses that examined at least one drug against placebo, another drug, or other standard therapy in asthma or COPD. Two reviewers independently searched and extracted data with differences adjudicated via consensus discussion. Data extracted included model used and its qualities, validation methods, treatments compared, disease severity, analytic perspective, time horizon, data collection (pro- or retrospective), input rates and sources, costs and sources, planned sensitivity analyses, criteria for cost-effectiveness, reported outcomes, and sponsor.
  
  
  RESULTS
  This study analyzed 53 articles; 14 (25%) on asthma and 39 (75%) COPD. Markov models were commonly used for both asthma and COPD-related economic evaluations. Relatively few studies validated their model. For asthma-related studies, 10 examined inhaled corticosteroids and nine studied omalizumab. Placebo or standard therapy was the comparison in 11 studies and active drugs in the remainder.
  
  
  CONCLUSIONS
  Few studies include validation of their models. Furthermore, controversy concerning some results was uncovered in this study, which needs to be avoided in the future.
authors.affiliation: a a Leslie Dan Faculty of Pharmacy, University of Toronto , Toronto , Canada.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Einarson
authors.affiliation: a a Leslie Dan Faculty of Pharmacy, University of Toronto , Toronto , Canada.
authors.forename: Basil G
authors.initials: BG
authors.lastname: Bereza
authors.affiliation: b b Janssen A/S , Birkerød , Denmark.
authors.forename: T Anders
authors.initials: TA
authors.lastname: Nielsen
authors.affiliation: c c Janssen Pharmaceutica NV , Beerse , Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Van Laer
authors.affiliation: b b Janssen A/S , Birkerød , Denmark.
authors.forename: Michiel E H
authors.initials: ME
authors.lastname: Hemels
mesh_terms: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents / Q000191:economics / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000191:economics*; D001993:Bronchodilator Agents / Q000191:economics / Q000627:therapeutic use; D003661:Decision Support Techniques; D006801:Humans; D017059:Models, Econometric; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000191:economics*; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents
keywords: Asthma; COPD; Economic evaluations; Validation