title: Cost-effectiveness analysis of the Xpert MTB/RIF assay for rapid diagnosis of suspected tuberculosis in an intermediate burden area.
abstract: OBJECTIVE
  We examined, from a Hong Kong healthcare providers' perspective, the cost-effectiveness of rapid diagnosis with Xpert in patients hospitalized for suspected active pulmonary tuberculosis (PTB).
  
  
  METHODS
  A decision tree was designed to simulate outcomes of three diagnostic assessment strategies in adult patients hospitalized for suspected active PTB: conventional approach, sputum smear plus Xpert for acid-fast bacilli (AFB) smear-negative, and a single sputum Xpert test. Model inputs were derived from the literature. Outcome measures were direct medical cost, one-year mortality rate, quality-adjusted life-years (QALYs) and incremental cost per QALY (ICER).
  
  
  RESULTS
  In the base-case analysis, Xpert was more effective with higher QALYs gained and a lower mortality rate when compared with smear plus Xpert by an ICER of USD99. A conventional diagnostic approach was the least preferred option with the highest cost, lowest QALYs gained and highest mortality rate. Sensitivity analysis showed that Xpert would be the most cost-effective option if the sensitivity of sputum AFB smear microscopy was ≤74%. The probabilities of Xpert, smear plus Xpert and a conventional approach to be cost-effective were 94.5%, 5.5% and 0%, respectively, in 10,000 Monte Carlo simulations.
  
  
  CONCLUSIONS
  The Xpert sputum test appears to be a highly cost-effective diagnostic strategy for patients with suspected active PTB in an intermediate burden area like Hong Kong.
authors.affiliation: School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong. Electronic address: joyceyou@cuhk.edu.hk.
authors.forename: Joyce H S
authors.initials: JH
authors.lastname: You
authors.affiliation: Division of Infectious Diseases, Department of Medicine & Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Grace
authors.initials: G
authors.lastname: Lui
authors.affiliation: Stanley Ho Centre for Emerging Infectious Diseases, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Kai Man
authors.initials: KM
authors.lastname: Kam
authors.affiliation: Division of Infectious Diseases, Department of Medicine & Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Nelson L S
authors.initials: NL
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D005260:Female; D006723:Hong Kong; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009010:Monte Carlo Method; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000191:economics*; D019057:Quality-Adjusted Life Years; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000191:economics* / Q000401:mortality
keywords: Cost-effectiveness; Decision-analytic model; Hong Kong; Rapid testing; Tuberculosis