title: Methods Used in Economic Evaluations of Tuberculin Skin Tests and Interferon Gamma Release Assays for the Screening of Latent Tuberculosis Infection: A Systematic Review.
abstract: BACKGROUND
  Latent tuberculosis infection (LTBI) provides a constant pool of new active tuberculosis cases; a third of the earth's population is estimated to be infected with LTBI.
  
  
  OBJECTIVE
  The objective of this systematic review was to assess the quality and summarize the available evidence from published economic evaluations reporting on the cost-effectiveness of tuberculin skin tests (TSTs) compared with interferon gamma release assays (IGRAs) for the screening of LTBI.
  
  
  METHODS
  An extensive systematic review of the published literature was conducted. A two-step process was adopted to identify relevant articles: information was extracted into evidence tables and then analyzed. The quality of the publications was assessed using a 10-item checklist specific for economic evaluations.
  
  
  RESULTS
  Twenty-eight studies were identified for inclusion in this review. Most of the studies found IGRAs to be more cost-effective than TSTs; however, the conclusions from the studies varied significantly. Most studies scored highly on the checklist although only one fulfilled all the stipulated criteria. A wide variety of methodological approaches were documented; identified differences included the type of economic evaluation and model, time horizon, perspective, and outcomes measures.
  
  
  CONCLUSIONS
  The lack of consistent methods across studies makes it difficult to draw any firm conclusions about the most cost-effective option between TSTs and IGRAs. This problem can be solved by improving the quality of economic evaluation studies in the field of LTBI screening, through adherence to quality checklists.
authors.affiliation: Health Economics Unit, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Maria
authors.initials: M
authors.lastname: Koufopoulou
authors.affiliation: Health Economics Unit, University of Birmingham, Birmingham, United Kingdom. Electronic address: a.j.sutton@leeds.ac.uk.
authors.forename: Andrew John
authors.initials: AJ
authors.lastname: Sutton
authors.affiliation: Health Economics Unit, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Katie
authors.initials: K
authors.lastname: Breheny
authors.affiliation: Health Economics Unit, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Lavanya
authors.initials: L
authors.lastname: Diwakar
mesh_terms: D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D017048:Health Care Costs; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics*; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000191:economics* / Q000276:immunology / Q000382:microbiology / Q000628:therapy; D018803:Models, Economic; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D014374:Tuberculin Test / Q000191:economics*
keywords: economic evaluations; interferon gamma release assays; screening; systematic review; tuberculin skin tests; tuberculosis