title: Cost effectiveness of high resolution computed tomography with interferon-gamma release assay for tuberculosis contact investigation.
abstract: BACKGROUND
  Tuberculosis contact investigation is one of the important public health strategies to control tuberculosis worldwide. Recently, high resolution computed tomography (HRCT) has been reported as a more accurate radiological method with higher sensitivity and specificity than chest X-ray (CXR) to detect active tuberculosis. In this study, we assessed the cost effectiveness of HRCT compared to CXR in combination with QuantiFERON(®)-TB Gold In-Tube (QFT) or the tuberculin skin test (TST) for tuberculosis contact investigation.
  
  
  METHODS
  We constructed Markov models using a societal perspective on the lifetime horizon. The target population was a hypothetical cohort of immunocompetent 20-year-old contacts with smear-positive tuberculosis patients in developed countries. Six strategies; QFT followed by CXR, QFT followed by HRCT, TST followed by CXR, TST followed by HRCT, CXR alone and HRCT alone were modeled. All costs and clinical benefits were discounted at a fixed annual rate of 3%.
  
  
  RESULTS
  In the base-case analysis, QFT followed by HRCT strategy yielded the greatest benefit at the lowest cost ($US 6308.65; 27.56045 quality-adjusted life-years [QALYs])[year 2012 values]. Cost-effectiveness was sensitive to BCG vaccination rate.
  
  
  CONCLUSIONS
  The QFT followed by HRCT strategy yielded the greatest benefits at the lowest cost. HRCT chest imaging, instead of CXR, is recommended as a cost effective addition to the evaluation and management of tuberculosis contacts in public health policy.
authors.affiliation: Kojiya Haneda Healthcare Service, Ota City Public Health Office, Tokyo, Japan. kowadaa@gmail.com
authors.forename: Akiko
authors.initials: A
authors.lastname: Kowada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016358:Contact Tracing / Q000191:economics* / Q000706:statistics & numerical data; D017048:Health Care Costs / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D059425:Interferon-gamma Release Tests / Q000191:economics* / Q000706:statistics & numerical data; D008403:Mass Screening / Q000191:economics* / Q000706:statistics & numerical data; D008875:Middle Aged; D011159:Population Surveillance; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000191:economics* / Q000706:statistics & numerical data; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000191:economics* / Q000453:epidemiology; D014481:United States; D055815:Young Adult