Cost-effectiveness of interferon-γ release assay testing for the treatment of latent tuberculosis

Abstract

The aim of the present study was to assess the cost-effectiveness of the new T-SPOT.TB assay versus the tuberculin skin test (TST) for screening contacts for latent tuberculosis (TB) infection in Switzerland.Health and economic outcomes of isoniazid treatment of 20-and 40-yr-old close contacts were compared in a Markov model over a 20-yr period following screening with TST only (at three cutoff values) and T-SPOT.TB alone or in combination with the TST.T-SPOT.TB-based treatment was cost-effective at J11,621 and J23,692 per life-year-gained (LYG) in the younger and older age group, respectively. No TST-based programmes were costeffective, except at a 15-mm cut-off in the younger group only, where the cost-effectiveness (J26,451?LYG -1 ) fell just below the willingness-to-pay threshold. Combination of the TST with T-SPOT.TB slightly reduced the total cost compared with the T-SPOT.TB alone by 4.4 and 5.0% in the younger and older groups respectively. The number of contacts treated to avoid one case of TB decreased from 50 (95% confidence interval 32-106) with the TST (10-mm cut-off) to 18 (95%CI 11-43) if T-SPOT.TB was used. Using T-SPOT.TB alone or in combination with the tuberculin skin test for screening of close contacts before latent tuberculosis infection treatment is highly cost-effective in reducing the disease burden of tuberculosis.KEYWORDS: Cost-effectiveness, interferon-c release assay, latent tuberculosis infection, latent tuberculosis infection treatment, tuberculosis S creening the contacts of patients with tuberculosis (TB) is recommended as a strategy to detect infected persons who may develop the disease at a later time. It has been demonstrated that preventive treatment, mainly with isoniazid, decreases the number of future cases of TB. This strategy is therefore recommended in countries with a low incidence rate of TB, in order to further decrease the burden of disease [1]. The effectiveness and cost-effectiveness of these programmes are strongly affected by the accuracy of identifying truly infected individuals who have a risk of developing future disease. Owing to the limited sensitivity and specificity of the tuberculin skin test (TST), it follows that the current cost-effectiveness of screening may be improved if more accurate tools are used for screening for latent tuberculosis infection (LTBI).Numerous studies screening recent contacts of infectious TB patients for LTBI using the new highly specific interferon-c release assays (IGRA) have recently been published [2][3][4][5][6][7], but no study has produced cost-effectiveness data. In two papers [8,9] the way in which IGRA can be used for cost-saving in initial screening has been discussed. However, the long-term economic consequences and healthcare outcomes of this new approach for detecting Mycobacterium tuberculosis infection were not examined in the context of subsequent treatment of LTBI in comparison with existing programmes based upon the TST.As intervention options in all therapeutic areas grow, government and third-party...

An Evaluation of the Latent Tuberculosis Control Program in the United States Military at Accession

“…Diel performed two cost-effectiveness analyses, one of QFT and one of T-Spot in which he found that testing of contacts of active TB cases was cost-effective, similar to TST. [165,166] Wrighton-Smith found similar results, suggesting that sequential testing of TST followed by IGRA may be a more cost-effective strategy. [167] On the other hand, Oxlade found that IGRA was the least cost-effective strategy for testing of immigrants.…”

Utilidad del Quantiferon-TB Gold in Tube® en el cribado de la infección latente tuberculosa en personal sanitario

“…Diel et al 44 van todavía más allá y analizan el coste-efectividad del otro test IGRA, el T SPOT TB, encontrado que igualmente es más efectivo que la PT en el cribado de contactos por 1.000 individuos. En Estados Unidos, Dewan et al 45 valoran en 2006 el coste del quantiferon en 33,6 dólares, similar al de otras publicaciones.…”

Old ideas to innovate tuberculosis control: preventive treatment to achieve elimination

“…These analyses reveal the major limitations of current LTBI prevention strategies, namely that a high number of high-risk persons must still be treated to prevent a single TB case. Even when screening with a highly specific IGRA tool and subsequently treating those scored positive, assuming an 80% IPT efficacy for the subgroup of ''completercompliers'', the NNT is not less than 12 individuals with LTBI [63]. As none of the currently available tests for LTBI (table 4), can accurately predict who will develop active TB among truly infected persons, the search for better diagnostic tools for LTBI must continue.…”