Authors: Marra, F.1; Marra, C.A.2; Sadatsafavi, M.3; Morán-Mendoza, O.4; Cook, V.1; Elwood, R.K.5; Morshed, M.5; Brunham, R.C.5; FitzGerald, J.M.6
Source: The International Journal of Tuberculosis and Lung Disease, Volume 12, Number 12, December 2008 , pp. 1414-1424(11)
Publisher: International Union Against Tuberculosis and Lung Disease
BACKGROUND: Recent approval of interferon-gamma release assays that are more specific for Mycobacterium tuberculosis has given new options for the diagnosis of latent tuberculosis infection (LTBI).
OBJECTIVE: To assess the cost-effectiveness of Quanti-FERON®-TB Gold (QFT-G) vs. the tuberculin skin test (TST) in diagnosing LTBI in contacts of active TB cases using a decision analytic Markov model.
METHODS: Three screening strategies—TST alone, QFT-G alone and sequential screening of TST then QFT-G—were evaluated. The model was further stratified according to ethnicity and bacille Calmette-Guérin (BCG) vaccination status. Data sources included published studies and empirical data. Results were reported in terms of the incremental net monetary benefit (INMB) of each strategy compared with the baseline strategy of TST-based screening in all contacts.
RESULTS: The most economically attractive strategy was to administer QFT-G in BCG-vaccinated contacts, and to reserve TST for all others (INMB CA$3.70/contact). The least cost-effective strategy was QFT-G for all contacts, which resulted in an INMB of CA$−11.50 per contact. Assuming a higher prevalence of recent infection, faster conversion of QFT-G, a higher rate of TB reactivation, reduction in utility or greater adherence to preventive treatment resulted in QFT-G becoming cost-effective in more subgroups.
CONCLUSIONS: Selected use of QFT-G appears to be cost-effective if used in a targeted fashion.
Keywords: cost-effectiveness analysis; tuberculosis; QuantiFERON TB-Gold; contacts; interferon gamma release assays
Document Type: Regular paper
Affiliations: 1: University of British Columbia, Vancouver, British Columbia, Canada; British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada 2: University of British Columbia, Vancouver, British Columbia, Canada; and Centre for Health Evaluation and Outcome Sciences, Vancouver, British Columbia, Canada 3: University of British Columbia, Vancouver, British Columbia, Canada 4: Faculty of Medicine, Division of Respiratory and Critical Care Medicine, Queen's University, Kingston, Ontario, Canada; Faculty of Medicine, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico 5: University of British Columbia, Vancouver, British Columbia, Canada; and British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada 6: University of British Columbia, Vancouver, British Columbia, Canada; and Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada