Cost-effectiveness of newer technologies for the diagnosis of Mycobacterium tuberculosis infection in Brazilian people living with HIV

Abstract

Tuberculosis is the leading cause of death among people living with HIV (PLH). Preventive tuberculosis therapy reduces mortality in PLH, especially in those with a positive tuberculin skin test (TST). New, more specific technologies for detecting latent tuberculosis infection (LTBI) are now commercially available. We sought to analyse the cost-effectiveness of four different strategies for the diagnosis of LTBI in PLH in Brazil, from the Brazilian public health care system perspective. We developed a Markov state-transition model comparing four strategies for the diagnosis of LTBI over 20 years. The strategies consisted of TST with the currently used protein purified derivative (PPD RT 23), two novel skin tests using recombinant allergens (Diaskintest [Generium Pharmaceutical, Moscow, Russia] and EC [Zhifei Longcom Biologic Pharmacy Co., Anhui, China]), and the QuantiFERON-TB-Gold-Plus (Qiagen, Hilden, Germany). The main outcome was cost (in 2020 US dollars) per quality-adjusted life years (QALY). For the base case scenario, the Diaskintest was dominant over all other examined strategies. The cost saving estimate per QALY was US $1375. In sensitivity analyses, the Diaskintest and other newer tests remained cost-saving compared to TST. For PLH, TST could be replaced by more specific tests in Brazil, considering the current national recommendations.

Differential Diagnosis of Latent Tuberculosis Infection and Active Tuberculosis: A Key to a Successful Tuberculosis Control Strategy

“…These skin tests have the advantages of the TST and IGRAs, which are characterized by simple operation, low cost, and easy reading of results, making it possible to apply them in countries with a high burden of TB and in poverty-stricken areas, especially in countries implementing universal BCG vaccination. Furthermore, increasingly emerging studies have demonstrated that these new skin tests show similar test positivity rates, safety profiles, and specificities to those of IGRAs and provide comparable results in terms of diagnosing patients with TB living with HIV and children infected with M. tuberculosis (Table 1; Litvinov et al, 2009;Aggerbeck et al, 2013;Hoff et al, 2016;Ruhwald et al, 2017;Aggerbeck et al, 2018;Steffen et al, 2020). Nevertheless, the potential drawbacks of these three new skin tests are worth noting.…”

“…In addition to the conventional TST, three novel strategies for the diagnosis of TB have been developed in recent years-Diaskintest (Generium Pharmaceutical, Moscow, Russia), C-Tb skin test (Statens Serum Institut, Copenhagen, Denmark), and EC-Test (Zhifei Longcom Biologic Pharmacy Co., Anhui, China) (Steffen et al, 2020;WHO, 2020). The Diaskintest is a new effective way to identify the initial presentation of TB and developed based on a fusion protein of the early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens present in virulent strains of M. tuberculosis, which are absent in the BCG strain and in most NTMs.…”

Cost-effectiveness of testing for latent tuberculosis infection in people with HIV

“…Base-case results from Kowada [13] showed that T-SPOT.TB dominated all other strategies whereas our results showed that T-SPOT.TB was dominated by QFT-GIT. Steffen et al [14] showed that new emerging tests (e.g. Diaskintest and QFT-Plus) were cost-saving against TST.…”

“…A scoping search of the literature identified five studies [13][14][15][16][17] that assessed the cost-effectiveness of diagnostic strategies for identifying LTBI in PWH. These studies provide useful clinical and economic evidence that may be used to support recommendations but there were several limitations noted.…”

“…These studies provide useful clinical and economic evidence that may be used to support recommendations but there were several limitations noted. First, the sensitivity and specificity used in two economic analyses [13,14] were obtained from systematic reviews [18][19][20] where the authors excluded studies with participants who were immunocompromised/immunosuppressed. Also, the sensitivities reported for QFT-GIT and T-SPOT.TB were for identifying active TB, and not LTBI.…”