Cost and cost-effectiveness of tuberculosis treatment shortening: a model-based analysis.

BACKGROUND: Despite improvements in treatment success rates for tuberculosis (TB), current six-month regimen duration remains a challenge for many National TB Programmes, health systems, and patients. There is increasing investment in the development of shortened regimens with a number of candidates in phase 3 trials. METHODS: We developed an individual-based decision analytic model to assess the cost-effectiveness of a hypothetical four-month regimen for first-line treatment of TB, assuming non-inferiority to current regimens of six-month duration. The model was populated using extensive, empirically-collected data to estimate the economic impact on both health systems and patients of regimen shortening for first-line TB treatment in South Africa, Brazil, Bangladesh, and Tanzania. We explicitly considered 'real world' constraints such as sub-optimal guideline adherence. RESULTS: From a societal perspective, a shortened regimen, priced at USD1 per day, could be a cost-saving option in South Africa, Brazil, and Tanzania, but would not be cost-effective in Bangladesh when compared to one gross domestic product (GDP) per capita. Incorporating 'real world' constraints reduces cost-effectiveness. Patient-incurred costs could be reduced in all settings. From a health service perspective, increased drug costs need to be balanced against decreased delivery costs. The new regimen would remain a cost-effective option, when compared to each countries' GDP per capita, even if new drugs cost up to USD7.5 and USD53.8 per day in South Africa and Brazil; this threshold was above USD1 in Tanzania and under USD1 in Bangladesh. CONCLUSION: Reducing the duration of first-line TB treatment has the potential for substantial economic gains from a patient perspective. The potential economic gains for health services may also be important, but will be context-specific and dependent on the appropriate pricing of any new regimen.

La ventaja epidemiológica de la orientación preferencial del control de la tuberculosis hacia los pobres

La tuberculosis (TB) continúa concentrada de manera desproporcionada entre los pobres, pero los determinantes conocidos de reactivación de la TB pueden no explicar las desigualdades observadas en las tasas de enfermedad según la riqueza. En el presente estudio, mediante la revisión de datos sobre desigualdades en TB en la India y la distribución de factores de riesgo de TB conocidos según riqueza, se describe cómo los patrones de mezcla social pueden estar contribuyendo a las desigualdades en TB. La mezcla social por afinidad selectiva según la riqueza, por la cual es más probable que las personas entren en contacto con otras personas de orígenes socioeconómicos similares, amplifica las pequeñas diferencias en el riesgo de TB y genera grandes desigualdades a nivel poblacional. A medida que las desigualdades y la asortatividad (o afinidad selectiva) aumentan, se hace más difícil controlar la TB; este efecto queda enmascarado cuando se examinan solamente promedios poblacionales de parámetros epidemiológicos, tales como las tasas de detección de casos. El estudio ilustra cómo los esfuerzos de control de TB pueden beneficiarse a partir de una orientación preferencial hacia los pobres. En la India, una intervención a escala equivalente podría tener un impacto sustancialmente mayor si se orientara a quienes viven por debajo de la línea de pobreza que el de una estrategia a toda la población. Además de las eficiencias potenciales de focalizar en poblaciones en más alto riesgo, los esfuerzos de control de la TB podrían llevar a una mayor reducción en el número de casos secundarios de TB por cada caso primario diagnosticado si es que tales esfuerzos fuesen preferencialmente orientados hacia los pobres. El estudio destaca la necesidad de recolectar datos programáticos sobre las desigualdades en TB e incorporar de manera explícita consideraciones de equidad en los planes de control de la TB.

La ventaja epidemiológica de la orientación preferencial del control de la tuberculosis hacia los pobres / The epidemiological advantage of preferential targeting of tuberculosis control at the poor

La tuberculosis (TB) continúa concentrada de manera desproporcionada entre los pobres, pero los determinantes conocidos de reactivación de la TB pueden no explicar las desigualdades observadas en las tasas de enfermedad según la riqueza. En el presente estudio, mediante la revisión de datos sobre desigualdades en TB en la India y la distribución de factores de riesgo de TB conocidos según riqueza, se describe cómo los patrones de mezcla social pueden estar contribuyendo a las desigualdades en TB. La mezcla social por afinidad selectiva según la riqueza, por la cual es más probable que las personas entren en contacto con otras personas de orígenes socioeconómicos similares, amplifica las pequeñas diferencias en el riesgo de TB y genera grandes desigualdades a nivel poblacional. A medida que las desigualdades y la asortatividad (o afinidad selectiva) aumentan, se hace más difícil controlar la TB; este efecto queda enmascarado cuando se examinan solamente promedios poblacionales de parámetros epidemiológicos, tales como las tasas de detección de casos. El estudio ilustra cómo los esfuerzos de control de TB pueden beneficiarse a partir de una orientación preferencial hacia los pobres. En la India, una intervención a escala equivalente podría tener un impacto sustancialmente mayor si se orientara a quienes viven por debajo de la línea de pobreza que el de una estrategia a toda la población. Además de las eficiencias potenciales de focalizar en poblaciones en más alto riesgo, los esfuerzos de control de la TB podrían llevar a una mayor reducción en el número de casos secundarios de TB por cada caso primario diagnosticado si es que tales esfuerzos fuesen preferencialmente orientados hacia los pobres. El estudio destaca la necesidad de recolectar datos programáticos sobre las desigualdades en TB e incorporar de manera explícita consideraciones de equidad en los planes de control de la TB.

Tuberculosis (TB) remains disproportionately concentrated among the poor, yet known determinants of TB reactivation may fail to explain observed disparities in disease rates according to wealth. Reviewing data on TB disparities in India and the wealth distribution of known TB risk factors, we describe how social mixing patterns could be contributing to TB disparities. Wealth-assortative mixing, whereby individuals are more likely to be in contact with others from similar socio-economic backgrounds, amplifies smaller differences in risk of TB, resulting in large population-level disparities. As disparities and assortativeness increase, TB becomes more difficult to control, an effect that is obscured by looking at population averages of epidemiological parameters, such as case detection rates. We illustrate how TB control efforts may benefit from preferential targeting toward the poor. In India, an equivalent-scale intervention could have a substantially greater impact if targeted at those living below the poverty line than with a population-wide strategy. In addition to potential efficiencies in targeting higher-risk populations, TB control efforts would lead to a greater reduction in secondary TB cases per primary case diagnosed if they were preferentially targeted at the poor. We highlight the need to collect programmatic data on TB disparities and explicitly incorporate equity considerations into TB control plans.

Cost-effectiveness of tuberculosis screening and isoniazid treatment in the TB/HIV in Rio (THRio) Study.

OBJECTIVE: To estimate the incremental cost-effectiveness of tuberculosis (TB) screening and isoniazid preventive therapy (IPT) among human immunodeficiency virus (HIV) infected adults in Rio de Janeiro, Brazil. DESIGN: We used decision analysis, populated by data from a cluster-randomized trial, to project the costs (in 2010 USD) and effectiveness (in disability-adjusted life years [DALYs] averted) of training health care workers to implement the tuberculin skin test (TST), followed by IPT for TST-positive patients with no evidence of active TB. This intervention was compared to a baseline of usual care. We used time horizons of 1 year for the intervention and 20 years for disease outcomes, with all future DALYs and medical costs discounted at 3% per year. RESULTS: Providing this intervention to 100 people would avert 1.14 discounted DALYs (1.57 undiscounted DALYs). The median estimated incremental cost-effectiveness ratio was $2273 (IQR $1779-$3135) per DALY averted, less than Brazil's 2010 per capita gross domestic product (GDP) of $11,700. Results were most sensitive to the cost of providing the training. CONCLUSION: Training health care workers to screen HIV-infected adults with TST and provide IPT to those with latent tuberculous infection can be considered cost-effective relative to the Brazilian GDP per capita.

Quality of life among people treated for tuberculosis and human immunodeficiency virus in Rio de Janeiro, Brazil.

We measured quality of life (QOL) among individuals receiving treatment for human immunodeficiency virus (HIV; n = 45), active tuberculosis (TB; n = 44) and both TB and HIV (n = 9) in Rio de Janeiro, Brazil. Active treated TB was associated with lower physical health (absolute decrease of 0.95 standard deviation in summary score), but not mental health, among people being treated for HIV. Visual analogue scale scores were similar across all three populations, and corresponded closely to standard disability weights used in the literature. Among patients receiving treatment, those with HIV, active TB and both conditions together appear to have similar QOL.

Cost-effectiveness of novel diagnostic tools for the diagnosis of tuberculosis.

SETTING: The potential cost-effectiveness of improved diagnostic tests for tuberculosis (TB) in resource-limited settings is unknown. OBJECTIVE: To estimate the incremental cost-effectiveness of a hypothetical new point-of-care TB diagnostic test in South Africa, Brazil and Kenya. DESIGN: Decision-analysis model, adding four diagnostic interventions (sputum smear microscopy, new test, smear plus new test and smear plus TB culture) to a baseline of existing infrastructure without smear. RESULTS: Adding sputum smear was estimated to be more cost-effective (incremental cost per disability-adjusted life year [DALY] of $86 [South Africa], $131 [Brazil], $38 (Kenya]) than a new TB diagnostic with 70% sensitivity, 95% specificity and price of $20 per test ($198 [South Africa], $275 [Brazil], $84 [Kenya]). However, compared to sputum smear, smear plus new test averted 46-49% more DALYs per 1000 TB suspects (321 vs. 215 [South Africa], 243 vs. 166 [Brazil], 790 vs. 531 [Kenya]), at an incremental cost of $170 (Kenya) to $625 (Brazil) per DALY averted. Cost-effectiveness was most sensitive to the specificity and price of the new test, the baseline TB case detection rate and the discount rate. CONCLUSION: Novel diagnostic tests for TB are potentially highly cost-effective. Cost-effectiveness is maximized by high-specificity, low-cost tests deployed to regions with poor infrastructure.