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. 2014 Oct;18(10):1159-65.
doi: 10.5588/ijtld.13.0571.

Cost-effectiveness of the Three I's for HIV/TB and ART to prevent TB among people living with HIV

S Gupta  1 , T Abimbola  2 , A Date  2 , A B Suthar  3 , R Bennett  4 , N Sangrujee  2 , R Granich  1
Affiliations

Cost-effectiveness of the Three I's for HIV/TB and ART to prevent TB among people living with HIV

S Gupta et al. Int J Tuberc Lung Dis. 2014 Oct.

Abstract
in English, French, Spanish

Objective: To evaluate the cost-effectiveness of the Three I's for HIV/TB (human immunodeficiency virus/tuberculosis): antiretroviral therapy (ART), intensified TB case finding (ICF), isoniazid preventive treatment (IPT), and TB infection control (IC).

Methods: Using a 3-year decision-analytic model, we estimated the cost-effectiveness of a base scenario (55% ART coverage at CD4 count ⩿350 cells/mm(3)) and 19 strategies that included one or more of the following: 1) 90% ART coverage, 2) IC and 3) ICF using four-symptom screening and 6- or 36-month IPT. The TB diagnostic algorithm included 1) sputum smear microscopy with chest X-ray, and 2) Xpert® MTB/RIF.

Results: In resource-constrained settings with a high burden of HIV and TB, the most cost-effective strategies under both diagnostic algorithms included 1) 55% ART coverage and IC, 2) 55% ART coverage, IC and 36-month IPT, and 3) expanded ART at 90% coverage with IC and 36-month IPT. The latter averted more TB cases than other scenarios with increased ART coverage, IC, 6-month IPT and/or IPT for tuberculin skin test positive individuals. The cost-effectiveness results did not change significantly under the sensitivity analyses.

Conclusion: Expanded ART to 90% coverage, IC and a 36-month IPT strategy averted most TB cases and is among the cost-effective strategies.

CONTEXTE: Nous évaluons le rapport coût-efficacité de l’approche des « 3 I » dans la lutte contre le virus de l’immunodéficience humaine (VIH) et la TB : traitement antirétroviral (ART) et intensification de la recherche de cas de TB (ICF), traitement préventif par isoniazide (IPT) et lutte contre l’infection tuberculeuse (IC).

MÉTHODES: Nous avons estimé, grâce à un modèle de décision analytique de 3 ans, le rapport coût-efficacité d’un scénario de base (55% de couverture du traitement ART quand la numération des CD4 est ≤350 cellules/mm3) et 19 stratégies qui incluaient une ou plusieurs des stratégies suivantes : 1) 90% de couverture par ART, 2) IC et 3) ICF grâce à un dépistage basé sur quatre symptômes et un IPT pendant 6 ou 36 mois. L’algorithme de diagnostic de la TB incluait 1) microscopie des frottis de crachats et radio pulmonaire et 2) Xpert® MTB/RIF.

RÉSULTATS: Dans les contextes ressources limitées confrontés à un lourd fardeau de VIH et de TB, les stratégies les plus rentables en termes d’algorithmes de diagnostic incluaient 1) 55% de couverture par ART et IC; 2) 55 % de couverture par ART, IC et 36 mois d’IPT; et 3) expansion de l’ART à une couverture de 90% avec IC et IPT de 36 mois. Cette dernière stratégie a évité davantage de cas de TB que les autres scénarios avec augmentation de la couverture par ART, IC, 6 mois d’IPT et/ou IPT pour les cas positifs au test cutané tuberculinique. Les résultats en termes de coût-efficacité n’ont pas changé significativement avec les analyses de sensibilité.

CONCLUSION: La stratégie d’expansion de la couverture par ART à 90%, IC et 36 mois d’IPT a évité le plus de cas de TB et elle est parmi les stratégies les plus rentables.

MARCO DE REFERENClA: Se llevó a cabo una evaluación de la rentabilidad de las intervenciones de prevención de la tuberculosis (TB), el tratamiento antirretrovírico (ART) y la estrategia de las ‘Tres íes’ (que comporta la intensificación de la búsqueda de casos [ICF] de coinfección por el virus de la inmunodeficiencia humana [VIH] y TB, el tratamiento preventive con isoniazida [IPT] y el control de la infección [IC] tuberculosa).

MÉTODOS: Se construyó unmodelo analítico decisional destinado a evaluar en una población positiva frente al VIH durante un período de 3 años, la rentabilidad de la prevención de la TB en un contexto hipotético de base (cobertura del 55% con el ART en pacientes con recuentos de linfocitos CD4 ≤350 células/µl) y en 19 estrategias comparativas que comportaban una o varias de las siguientes condiciones: 1) una cobertura del 90% con el ART, 2) medidas de IC tuberculosa y 3) la ICF mediante un sistema de detección por cuatro síntomas y el IPT durante 6 meses o 36 meses en los casos negatives. Se compararon todas las estrategias al usar dos algoritmos diagnósticos diferentes: 1) la baciloscopia del esputo con radiografía de tórax y 2) la prueba Xpert® MTB/RIF.

RESULTADOS: En los entornos con recursos limitados y una alta carga de morbilidad por TB e infección por el VIH, las estrategias más rentables con ambos algoritmos diagnósticos fueron: 1) una cobertura del 55% con el ART y las medidas de IC tuberculosa; 2) una cobertura del 55% con el ART y 36 meses de IPT; y 3) la ampliación de la cobertura con el ART al 90%, con medidas de IC tuberculosa y 36 meses de IPT. Esta última estrategia evitó más casos de TB que otras dos hipótesis con ampliación de la cobertura a 90%, IC y 6 meses de IPT o con tratamiento preventive en los casos de reacción tuberculínica positiva. Los resultados de rentabilidad no se modificaron de manera significativa en los análisis de sensibilidad.

CONCLUSION: La estrategia que comporta la ampliación de la cobertura con el ART a 90%, las medidas de IC tuberculosa y el IPT durante 36 meses evitó el mayor número de casos de TB y es rentable.

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Conflict of interest statement

Conflict of interest: none declared.

Figures

Figure A.1
Figure A.1
Decision tree. TB was diagnosed using sputum smear and chest radiography or Xpert® MTB/RIF. * Standard TB screening is using cough; enhanced TB screening refers to the WHO-recommended four-symptom screening algorithm. PLHIV = people living with HIV; TB = tuberculosis; IC = infection control;+= positive;-= negative; ART=antiretroviral therapy; TST = tuberculin skin test; IPT = isoniazid preventive therapy; WHO = World Health Organization.
Figure A.1
Figure A.1
Decision tree. TB was diagnosed using sputum smear and chest radiography or Xpert® MTB/RIF. * Standard TB screening is using cough; enhanced TB screening refers to the WHO-recommended four-symptom screening algorithm. PLHIV = people living with HIV; TB = tuberculosis; IC = infection control;+= positive;-= negative; ART=antiretroviral therapy; TST = tuberculin skin test; IPT = isoniazid preventive therapy; WHO = World Health Organization.
Figure A.2
Figure A.2
Probabilistic sensitivity analysis. A) Cost-effectiveness acceptability curve; B) strategy selection (willingness-to-pay/TB case averted = USD35 000). We ran 10 000 iterations of the model for Year 1 using Monte Carlo simulation probabilistic sensitivity analysis and compared the two most comprehensive strategies that were also among the cost-effective strategies (ART IC ICF IPT 36 and ARTexp IC ICF IPT 36, Xpert TB diagnostic algorithm). We set distribution for only those variables found to be influential in the oneway sensitivity analysis under the two willingness-to-pay thresholds of USD1000 and 35 000 (ART coverage, relative risk of TB from ART and from IC, cost of IC interventions and cost of IPT). The result of the probabilistic sensitivity analysis using the willingness-to-pay threshold of USD35 000 indicated that we will choose the ART IC ICF IPT 36 strategy 32% of the time and we will be indifferent between both the strategies 55% of the time. We will choose the ARTexp IC ICF IPT 36 strategy 13% of the time. Note that strategy selection is based on costs and outcomes of the scenarios in Year 1. The probability of choosing ARTexp IC ICF IPT 36 strategy is likely to be higher over a 3-year period. Furthermore, the probability of choosing the expanded ART strategy would likely be much higher if we include benefits of ART beyond the prevention of TB. ART=antiretroviral therapy; IC = infection control; ICF = intensified case finding; PT = isoniazid preventive therapy; ARTexp = expanded ART (90% coverage); USD = US dollars.
Figure A.3
Figure A.3
Expected costs and TB cases (TB diagnostic algorithm: sputum smear and chest radiography). Note: The description of the strategies (A to T) is given in Table 1. Base (A), ART IC (B), ART IC ICF IPT 36 (H) and ARTexp IC ICF IPT 36 (R) scenarios were most cost-effective. The total TB cases and total costs under each strategy are available in the Online Appendix. USD = US dollars; TB = tuberculosis; ART =antiretroviral therapy; IC = infection control; ICF = intensified case finding; IPT = isoniazid preventive therapy; ARTexp = expanded ART (90% coverage).
Figure A.4
Figure A.4
Expected costs and TB cases (TB diagnostic algorithm: Xpert® MTB/RIF assay). Note: The description of the strategies (A to T) is given in Table 1. Base (A), ART IC (B), ART IC ICF IPT 36 (H) and ARTexp IC ICF IPT 36 (R) scenarios were most cost-effective. The total TB cases and total costs under each strategy are available in the Online Appendix. USD = US dollars; TB = tuberculosis; ART=antiretroviral therapy; IC = infection control; ICF = intensified case finding; IPT= isoniazid preventive therapy; ARTexp = expanded ART (90% coverage).
Figure A.5
Figure A.5
Tornado diagram of univariate analyses for strategies with sputum smear and chest radiography for TB diagnosis. A) Willingness-to-pay threshold of USD1000. Note: the diagram shows the degree to which uncertainty in current ART coverage, specificity and sensitivity of TB screening with cough, the RR of TB from IC and ART and cost of IC interventions accounted for 100% variation in cost-effectiveness results. Variations in other parameters (cost of TST, IPT and anti-tuberculosis treatment, sensitivity and specificity of four-symptom screening, the RR of TB from 6-month or 36-month IPT, proportion of people testing TST-positive of those with active TB and without active TB, and expanded ART coverage) had no effect on the results. B) Willingness-to-pay threshold of USD35 000. Note: this diagram shows the degree to which uncertainty in RR of TB from continuous IPT vs. 6-month IPT, 6-month IPT for TST-negatives and IC and cost of 36-month IPT accounted for nearly 100% variation in cost-effectiveness results. Variations in other parameters (cost of TST and anti-tuberculosis treatment, sensitivity and specificity of TB screening using cough or four-symptom screening, proportion of people testing TST-positive of those with active TB and without active TB, and expanded ART coverage) had no effect on the results. ART = antiretroviral therapy; RR = relative risk; TB = tuberculosis; IC = infection control; IPT = isoniazid preventive therapy; TST = tuberculin skin test; USD = US dollars.
Figure A.6
Figure A.6
Tornado diagram of univariate analyses for strategies with Xpert® MTB/RIF for TB diagnosis. A) Willingness-to-pay threshold of USD1000. Note: the diagram shows the degree to which uncertainty in current ART coverage, specificity and sensitivity of TB screening with cough, RR of TB from IC and ART, and cost of IC interventions accounted for 100% variation in cost-effectiveness results. Variations in other parameters (cost of TST, IPT and anti-tuberculosis treatment; sensitivity and specificity of four-symptom screening; RR of TB from 6-month or 36-month IPT; proportion of people testing TST-positive of those with active TB and without active TB; and expanded ART coverage) had no effect on the results. B) Willingness-to-pay threshold of USD35 000. Note: this diagram shows the degree to which uncertainty in RR of TB from continuous IPT vs. 6-month IPT, 6-month IPT for TST-negative, and IC and cost of 36-months IPT accounted for nearly 100% variation in cost-effectiveness results. Variations in other parameters (cost of TST and anti-tuberculosis treatment; sensitivity and specificity of TB screening using cough; sensitivity of four-symptom screening; proportion of people testing TST-positive of those with active TB and without active TB; and expanded ART coverage) had no effect on the results. ART =antiretroviral therapy; RR = relative risk; TB = tuberculosis; IC = infection control; IPT = isoniazid preventive therapy; TST = tuberculin skin test; USD = US dollars.
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References

    1. World Health Organization. Global tuberculosis report, 2013. WHG7HTM/TB/2013.11. Geneva, Switzerland: WHO; 2013. [Accessed June 2014]. http://apps.who.int/iris/bitstream/10665/91355/1/9789241564656_eng.pdf.
    1. Joint United Nations Programme on HIV/AIDS. UNAIDS report on the global AIDS epidemic 2013. UNAIDS/JC2502/1/E. Geneva, Switzerland: UNAIDS; 2013. 2013. [Accessed June 2014]. http://www.unaids.org/en/media/unaids/contentassets/documents/epidemiolo....
    1. World Health Organization. Policy on collaborative TB/HIV activities: guidelines for national programmes and other stakeholders. WHO/HTM/TB/2012.1. WHO/HIV/2012.1. Geneva, Switzerland: WHO; 2012. [Accessed June 2014]. http://whqlibdoc.who.int/publications/2012/9789241503006_eng.pdf. - PubMed
    1. Suthar AB, Lawn SD, del Amo J, et al. Antiretroviral therapy for prevention of tuberculosis in adults with HIV: a systematic review and meta-analysis. PLOS MED. 2012;9:e1001270. - PMC - PubMed
    1. Middelkoop K, Bekker LG, Myer L, et al. Antiretroviral therapy and TB notification rates in a high HIV prevalence South African community. J Acquir Immune Defic Syndr. 2011;56:263–269. - PMC - PubMed