title: QuantiFERON-TB gold in-tube implementation for latent tuberculosis diagnosis in a public health clinic: a cost-effectiveness analysis.
abstract: BACKGROUND
  The tuberculin skin test (TST) has limitations for latent tuberculosis infection (LTBI) diagnosis in low-prevalence settings. Previously, all TST-positive individuals referred from the community to Baltimore City Health Department (BCHD) were offered LTBI treatment, after active TB was excluded. In 2010, BCHD introduced adjunctive QuantiFERON-TB Gold In-Tube (QFT-GIT) testing for TST-positive referrals. We evaluated costs and cost-effectiveness of this new diagnostic algorithm.
  
  
  METHODS
  A decision-analysis model compared the strategy of treating all TST-positive referrals versus only those with positive results on adjunctive QFT-GIT testing. Costs were collected at BCHD, and Incremental Cost-Effectiveness Ratios (ICERs) were utilized to report on cost-effectiveness.
  
  
  RESULTS
  QFT-GIT testing at BCHD cost $43.51 per test. Implementation of QFT-GIT testing was associated with an ICER of $1,202 per quality-adjusted life-year gained and was considered highly cost-effective. In sensitivity analysis, the QFT-GIT strategy became cost-saving if QFT-GIT sensitivity increased above 92% or if less than 3.5% of individuals with LTBI progress to active TB disease.
  
  
  CONCLUSIONS
  LTBI screening with TST in low-prevalence settings may lead to overtreatment and increased expenditures. In this public health clinic, additional QFT-GIT testing of individuals referred for a positive TST was cost-effective.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA. mshah28@jhmi.edu
authors.forename: Maunank
authors.initials: M
authors.lastname: Shah
authors.forename: Kathryn
authors.initials: K
authors.lastname: Miele
authors.forename: Howard
authors.initials: H
authors.lastname: Choi
authors.forename: Danielle
authors.initials: D
authors.lastname: DiPietro
authors.forename: Maria
authors.initials: M
authors.lastname: Martins-Evora
authors.forename: Vincent
authors.initials: V
authors.lastname: Marsiglia
authors.forename: Susan
authors.initials: S
authors.lastname: Dorman
mesh_terms: D003362:Cost-Benefit Analysis; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D055985:Latent Tuberculosis / Q000188:drug therapy* / Q000378:metabolism; D009010:Monte Carlo Method; D011634:Public Health / Q000191:economics
chemical_list: D007371:Interferon-gamma