title: [Comparative study of concordance and costs between tuberculin skin test and QuantiFERON(®)-TB Gold In-Tube in the diagnosis of latent tuberculosis infection among contacts of patients with pulmonary tuberculosis].
abstract: BACKGROUND
  Recently diagnosis of latent tuberculosis infection (LTBI) can be made using the tuberculin skin test (TST) or by techniques known as interferon-γ release assays (IGRAS), being QuantiFERON(®)-TB Gold In-Tube (QF-G-IT) the most used. The IGRAS avoid some drawbacks of the TST, especially cross-reaction with bacillus Calmette-Guérin (BCG) vaccine, but also present some problems such as those arising from cost and the need of having an adequate infrastructure and experience. There is no clear consensus on which technique should be preferentially used for the diagnosis of LTBI.
  
  
  METHODS
  This is a comparative study between the TST and QT-G-IT in a cohort of contacts of patients with pulmonary tuberculosis during the study period. An analysis of global agreement and groups was performed according to whether the contacts were vaccinated with BCG or not. A study of costs of both techniques and diagnostic strategies based on these techniques was performed.
  
  
  RESULTS
  The agreement between TST and QF-G-IT was acceptable in the whole sample yet it was very good in the unvaccinated group. Few cases of indeterminate values were recorded. The cost study showed that TST was cheaper than QF-G-IT; however when we analyzed the cost of the strategies according to each technique, the QF-G-IT showed a better cost-benefit.
  
  
  CONCLUSIONS
  We suggest considering QF-G-IT as the only preferred technique for the diagnosis of LTBI in household contacts, based on good overall agreement between the 2 techniques (even if we eliminate the effect of the vaccine) and a cost analysis favorable to QF-G-IT.
authors: Unitat de Control de Tuberculosis, Servei de Medicina Interna, Hospital Universitari Mútua Terrassa, Terrassa, Barcelona, España. Electronic address: xmartinez@mutuaterrassa.cat.
authors: Xavier
authors: X
authors: Martinez Lacasa
authors: Unitat de Control de Tuberculosis, Servei de Medicina Interna, Hospital Universitari Mútua Terrassa, Terrassa, Barcelona, España.
authors: Roser
authors: R
authors: Canals Font
authors: Fundació Recerca Mútua Terrassa, Terrassa, Barcelona, España.
authors: Angels
authors: A
authors: Jaen Manzanera
authors: CatLab, Terrassa, Barcelona, España.
authors: Eva
authors: E
authors: Cuchi Burgos
authors: CatLab, Terrassa, Barcelona, España.
authors: Josep
authors: J
authors: Lite Lite
mesh_terms: D000328:Adult; D000368:Aged; D016358:Contact Tracing; D003362:Cost-Benefit Analysis; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics*; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000191:economics / Q000635:transmission; D008297:Male; D008875:Middle Aged; D013030:Spain; D014374:Tuberculin Test / Q000191:economics*; D014397:Tuberculosis, Pulmonary / Q000635:transmission*
keywords: Análisis de liberación del interferón-γ; Concordance analysis; Cost-effectiveness analysis; Estudio de concordancia; Estudio de coste beneficio; Interferon-γ release assays; Prueba de la tuberculina; Pulmonary tuberculosis; QuantiFERON(®)-TB Gold In-Tube; Tuberculin skin test; Tuberculosis pulmonar