title: Systematic review of cost-effectiveness analyses of treatments for psoriasis.
abstract: BACKGROUND
  Psoriasis is a chronic inflammatory disease of the skin that has a major effect on an individual's physical and mental function. The disease is associated with increased healthcare resource use and costs, therefore cost-effectiveness analysis (CEA) can be used to assist decision makers with determining which treatments are optimal within a constrained healthcare system budget.
  
  
  OBJECTIVE
  Our aim was to systematically review the current literature on the CEA of existing treatment options for psoriasis, assess the quality of these studies, and summarize the evidence on the drivers of cost effectiveness.
  
  
  METHODS
  A literature search using Medical Subject Headings and keywords was performed in the MEDLINE, EMBASE and Health Technology Assessment databases, as well as the National Health Service Economic Evaluation Database; the CEA Registry was searched using keywords only. All references within the relevant review articles were examined manually. Two researchers independently determined the final articles and a third researcher resolved any discrepancies. We evaluated study quality in terms of the study perspective, effectiveness measures, cost measures, economic model, and time horizon. Any sensitivity analyses conducted in the studies were examined to identify the drivers of cost effectiveness, which included any variables leading to changes in the study conclusions.
  
  
  RESULTS
  Fifty-three articles were included in our final review: 70% did not explicitly include costs related to adverse events; approximately one-quarter used quality-adjusted life-years; and 34% applied a time horizon under 1 year. In 18 of the 38 studies that conducted a sensitivity analysis, the cost-effectiveness results were impacted by uncertainty. The main key drivers of cost effectiveness were the costs related to the treatment, values and choice of efficacy, utility values, hospitalization for non-responders, time horizon, model structure, and utility mapping method.
  
  
  CONCLUSIONS
  High-quality cost-effectiveness studies are required to facilitate resource allocation decision making. To improve study quality, future research should provide evidence on the long-term experience with psoriasis treatments, and resolve the uncertainty associated with key drivers of cost effectiveness.
authors.affiliation: Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, 588-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Nazrul
authors.initials: N
authors.lastname: Islam
authors.forename: Canice
authors.initials: C
authors.lastname: Ma
authors.forename: Aslam H
authors.initials: AH
authors.lastname: Anis
mesh_terms: D003362:Cost-Benefit Analysis; D003657:Decision Making; D006760:Hospitalization / Q000191:economics; D006801:Humans; D018803:Models, Economic; D011565:Psoriasis / Q000191:economics* / Q000628:therapy*; D019057:Quality-Adjusted Life Years; D040841:Resource Allocation