Journal Article > Meta-AnalysisFull Text
E Clinical Medicine. 2023 February 1; Volume 56; 101815.; DOI:10.1016/j.eclinm.2022.101815
Hamada Y, Gupta RS, Quartagno M, Izzard A, Acuna-Villaorduna C, et al.
E Clinical Medicine. 2023 February 1; Volume 56; 101815.; DOI:10.1016/j.eclinm.2022.101815
BACKGROUND
Evidence on the comparative performance of purified protein derivative tuberculin skin tests (TST) and interferon-gamma release assays (IGRA) for predicting incident active tuberculosis (TB) remains conflicting. We conducted an individual participant data meta-analysis to directly compare the predictive performance for incident TB disease between TST and IGRA to inform policy.
METHODS
We searched Medline and Embase from 1 January 2002 to 4 September 2020, and studies that were included in previous systematic reviews. We included prospective longitudinal studies in which participants received both TST and IGRA and estimated performance as hazard ratios (HR) for the development of all diagnoses of TB in participants with dichotomised positive test results compared to negative results, using different thresholds of positivity for TST. Secondary analyses included an evaluation of the impact of background TB incidence. We also estimated the sensitivity and specificity for predicting TB. We explored heterogeneity through pre-defined sub-group analyses (e.g. country-level TB incidence). Publication bias was assessed using funnel plots and Egger's test. This review is registered with PROSPERO, CRD42020205667.
FINDINGS
We obtained data from 13 studies out of 40 that were considered eligible (N = 32,034 participants: 36% from countries with TB incidence rate ≥100 per 100,000 population). All reported data on TST and QuantiFERON Gold in-Tube (QFT-GIT). The point estimate for the TST was highest with higher cut-offs for positivity and particularly when stratified by bacillus Calmette–Guérin vaccine (BCG) status (15 mm if BCG vaccinated and 5 mm if not [TST5/15 mm]) at 2.88 (95% CI 1.69–4.90). The pooled HR for QFT-GIT was higher than for TST at 4.15 (95% CI 1.97–8.75). The difference was large in countries with TB incidence rate <100 per 100,000 population (HR 10.38, 95% CI 4.17–25.87 for QFT-GIT VS. HR 5.36, 95% CI 3.82–7.51 for TST5/15 mm) but much of this difference was driven by a single study (HR 5.13, 95% CI 3.58–7.35 for TST5/15 mm VS. 7.18, 95% CI 4.48–11.51 for QFT-GIT, when excluding the study, in which all 19 TB cases had positive QFT-GIT results). The comparative performance was similar in the higher burden countries (HR 1.61, 95% CI 1.23–2.10 for QFT-GIT VS. HR 1.72, 95% CI 0.98–3.01 for TST5/15 mm). The predictive performance of both tests was higher in countries with TB incidence rate <100 per 100,000 population. In the lower TB incidence countries, the specificity of TST (76% for TST5/15 mm) and QFT-GIT (74%) for predicting active TB approached the minimum World Health Organization target (≥75%), but the sensitivity was below the target of ≥75% (63% for TST5/15 mm and 65% for QFT-GIT). The absolute differences in positive and negative predictive values between TST15 mm and QFT-GIT were small (positive predictive values 2.74% VS. 2.46%; negative predictive values 99.42% VS. 99.52% in low-incidence countries). Egger's test did not show evidence of publication bias (0.74 for TST15 mm and p = 0.68 for QFT-GIT).
INTERPRETATION
IGRA appears to have higher predictive performance than the TST in low TB incidence countries, but the difference was driven by a single study. Any advantage in clinical performance may be small, given the numerically similar positive and negative predictive values. Both IGRA and TST had lower performance in countries with high TB incidence. Test choice should be contextual and made considering operational and likely clinical impact of test results.
Evidence on the comparative performance of purified protein derivative tuberculin skin tests (TST) and interferon-gamma release assays (IGRA) for predicting incident active tuberculosis (TB) remains conflicting. We conducted an individual participant data meta-analysis to directly compare the predictive performance for incident TB disease between TST and IGRA to inform policy.
METHODS
We searched Medline and Embase from 1 January 2002 to 4 September 2020, and studies that were included in previous systematic reviews. We included prospective longitudinal studies in which participants received both TST and IGRA and estimated performance as hazard ratios (HR) for the development of all diagnoses of TB in participants with dichotomised positive test results compared to negative results, using different thresholds of positivity for TST. Secondary analyses included an evaluation of the impact of background TB incidence. We also estimated the sensitivity and specificity for predicting TB. We explored heterogeneity through pre-defined sub-group analyses (e.g. country-level TB incidence). Publication bias was assessed using funnel plots and Egger's test. This review is registered with PROSPERO, CRD42020205667.
FINDINGS
We obtained data from 13 studies out of 40 that were considered eligible (N = 32,034 participants: 36% from countries with TB incidence rate ≥100 per 100,000 population). All reported data on TST and QuantiFERON Gold in-Tube (QFT-GIT). The point estimate for the TST was highest with higher cut-offs for positivity and particularly when stratified by bacillus Calmette–Guérin vaccine (BCG) status (15 mm if BCG vaccinated and 5 mm if not [TST5/15 mm]) at 2.88 (95% CI 1.69–4.90). The pooled HR for QFT-GIT was higher than for TST at 4.15 (95% CI 1.97–8.75). The difference was large in countries with TB incidence rate <100 per 100,000 population (HR 10.38, 95% CI 4.17–25.87 for QFT-GIT VS. HR 5.36, 95% CI 3.82–7.51 for TST5/15 mm) but much of this difference was driven by a single study (HR 5.13, 95% CI 3.58–7.35 for TST5/15 mm VS. 7.18, 95% CI 4.48–11.51 for QFT-GIT, when excluding the study, in which all 19 TB cases had positive QFT-GIT results). The comparative performance was similar in the higher burden countries (HR 1.61, 95% CI 1.23–2.10 for QFT-GIT VS. HR 1.72, 95% CI 0.98–3.01 for TST5/15 mm). The predictive performance of both tests was higher in countries with TB incidence rate <100 per 100,000 population. In the lower TB incidence countries, the specificity of TST (76% for TST5/15 mm) and QFT-GIT (74%) for predicting active TB approached the minimum World Health Organization target (≥75%), but the sensitivity was below the target of ≥75% (63% for TST5/15 mm and 65% for QFT-GIT). The absolute differences in positive and negative predictive values between TST15 mm and QFT-GIT were small (positive predictive values 2.74% VS. 2.46%; negative predictive values 99.42% VS. 99.52% in low-incidence countries). Egger's test did not show evidence of publication bias (0.74 for TST15 mm and p = 0.68 for QFT-GIT).
INTERPRETATION
IGRA appears to have higher predictive performance than the TST in low TB incidence countries, but the difference was driven by a single study. Any advantage in clinical performance may be small, given the numerically similar positive and negative predictive values. Both IGRA and TST had lower performance in countries with high TB incidence. Test choice should be contextual and made considering operational and likely clinical impact of test results.
Journal Article > ReviewFull Text
Lancet Infect Dis. 2013 March 24; Volume 13 (Issue 5); DOI:10.1016/S1473-3099(13)70030-6
Abubakar I, Zignol M, Falzon D, Raviglione M, Ditui L, et al.
Lancet Infect Dis. 2013 March 24; Volume 13 (Issue 5); DOI:10.1016/S1473-3099(13)70030-6
Journal Article > ResearchFull Text
Int J Tuberc Lung Dis. 2016 March 1; Volume 20 (Issue 3); 290-294.; DOI:10.5588/ijtld.15.0490
Furin J, Alirol E, Allen E, Fielding K, Merle CS, et al.
Int J Tuberc Lung Dis. 2016 March 1; Volume 20 (Issue 3); 290-294.; DOI:10.5588/ijtld.15.0490
Drug-resistant tuberculosis (DR-TB) is a growing public health problem, and for the first time in decades, new drugs for the treatment of this disease have been developed. These new drugs have prompted strengthened efforts in DR-TB clinical trials research, and there are now multiple ongoing and planned DR-TB clinical trials. To facilitate comparability and maximise policy impact, a common set of core research definitions is needed, and this paper presents a core set of efficacy and safety definitions as well as other important considerations in DR-TB clinical trials work. To elaborate these definitions, a search of clinical trials registries, published manuscripts and conference proceedings was undertaken to identify groups conducting trials of new regimens for the treatment of DR-TB. Individuals from these groups developed the core set of definitions presented here. Further work is needed to validate and assess the utility of these definitions but they represent an important first step to ensure there is comparability in clinical trials on multidrug-resistant TB.
Journal Article > ReviewAbstract
J Infect Dis. 2012 April 3; Volume 205 (Issue suppl_2); DOI:10.1093/infdis/jir858
Zumla A, Abubakar I, Raviglione M, Hoelscher M, Ditui L, et al.
J Infect Dis. 2012 April 3; Volume 205 (Issue suppl_2); DOI:10.1093/infdis/jir858
Tuberculosis was declared a global emergency by the World Health Organization (WHO) in 1993. Following the declaration and the promotion in 1995 of directly observed treatment short course (DOTS), a cost-effective strategy to contain the tuberculosis epidemic, nearly 7 million lives have been saved compared with the pre-DOTS era, high cure rates have been achieved in most countries worldwide, and the global incidence of tuberculosis has been in a slow decline since the early 2000s. However, the emergence and spread of multidrug-resistant (MDR) tuberculosis, extensively drug-resistant (XDR) tuberculosis, and more recently, totally drug-resistant tuberculosis pose a threat to global tuberculosis control. Multidrug-resistant tuberculosis is a man-made problem. Laboratory facilities for drug susceptibility testing are inadequate in most tuberculosis-endemic countries, especially in Africa; thus diagnosis is missed, routine surveillance is not implemented, and the actual numbers of global drug-resistant tuberculosis cases have yet to be estimated. This exposes an ominous situation and reveals an urgent need for commitment by national programs to health system improvement because the response to MDR tuberculosis requires strong health services in general. Multidrug-resistant tuberculosis and XDR tuberculosis greatly complicate patient management within resource-poor national tuberculosis programs, reducing treatment efficacy and increasing the cost of treatment to the extent that it could bankrupt healthcare financing in tuberculosis-endemic areas. Why, despite nearly 20 years of WHO-promoted activity and >12 years of MDR tuberculosis-specific activity, has the country response to the drug-resistant tuberculosis epidemic been so ineffectual? The current dilemmas, unanswered questions, operational issues, challenges, and priority needs for global drug resistance screening and surveillance, improved treatment regimens, and management of outcomes and prevention of DR tuberculosis are discussed.
Journal Article > CommentaryFull Text
Eur Respir J. 2015 March 18; Volume 45 (Issue 4); DOI:10.1183/09031936.00214014
Lonnroth K, Migliori GB, Abubakar I, DAmbrosio L, de Vries G, et al.
Eur Respir J. 2015 March 18; Volume 45 (Issue 4); DOI:10.1183/09031936.00214014
This paper describes an action framework for countries with low tuberculosis (TB) incidence (<100 TB cases per million population) that are striving for TB elimination. The framework sets out priority interventions required for these countries to progress first towards "pre-elimination" (<10 cases per million) and eventually the elimination of TB as a public health problem (less than one case per million). TB epidemiology in most low-incidence countries is characterised by a low rate of transmission in the general population, occasional outbreaks, a majority of TB cases generated from progression of latent TB infection (LTBI) rather than local transmission, concentration to certain vulnerable and hard-to-reach risk groups, and challenges posed by cross-border migration. Common health system challenges are that political commitment, funding, clinical expertise and general awareness of TB diminishes as TB incidence falls. The framework presents a tailored response to these challenges, grouped into eight priority action areas: 1) ensure political commitment, funding and stewardship for planning and essential services; 2) address the most vulnerable and hard-to-reach groups; 3) address special needs of migrants and cross-border issues; 4) undertake screening for active TB and LTBI in TB contacts and selected high-risk groups, and provide appropriate treatment; 5) optimise the prevention and care of drug-resistant TB; 6) ensure continued surveillance, programme monitoring and evaluation and case-based data management; 7) invest in research and new tools; and 8) support global TB prevention, care and control. The overall approach needs to be multisectorial, focusing on equitable access to high-quality diagnosis and care, and on addressing the social determinants of TB. Because of increasing globalisation and population mobility, the response needs to have both national and global dimensions.
Journal Article > ReviewAbstract
J Infect Dis. 2012 April 10; Volume 205 (Issue suppl_2); DOI:10.1093/infdis/jir860
McNerney R, Maeurer M, Abubakar I, Marais BJ, McHugh TD, et al.
J Infect Dis. 2012 April 10; Volume 205 (Issue suppl_2); DOI:10.1093/infdis/jir860
Tuberculosis is unique among the major infectious diseases in that it lacks accurate rapid point-of-care diagnostic tests. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely fashion, allowing continued Mycobacterium tuberculosis transmission within communities. Currently recommended gold-standard diagnostic tests for tuberculosis are laboratory based, and multiple investigations may be necessary over a period of weeks or months before a diagnosis is made. Several new diagnostic tests have recently become available for detecting active tuberculosis disease, screening for latent M. tuberculosis infection, and identifying drug-resistant strains of M. tuberculosis. However, progress toward a robust point-of-care test has been limited, and novel biomarker discovery remains challenging. In the absence of effective prevention strategies, high rates of early case detection and subsequent cure are required for global tuberculosis control. Early case detection is dependent on test accuracy, accessibility, cost, and complexity, but also depends on the political will and funder investment to deliver optimal, sustainable care to those worst affected by the tuberculosis and human immunodeficiency virus epidemics. This review highlights unanswered questions, challenges, recent advances, unresolved operational and technical issues, needs, and opportunities related to tuberculosis diagnostics.