Cost-effectiveness of isoniazid preventive therapy for HIV-infected pregnant women in India

In-kind nutritional supplementation for household contacts of persons with tuberculosis would be cost-effective for reducing tuberculosis incidence and mortality in India: a modeling study

Background

Undernutrition is the leading cause of tuberculosis (TB) globally, but nutritional interventions are often considered cost prohibitive. The RATIONS study demonstrated that nutritional support provided to household contacts of persons with TB can reduce TB incidence. However, the long-term cost-effectiveness of this intervention is unclear.

Methods

We assessed the cost-effectiveness of a RATIONS-style intervention (daily 750 kcal dietary supplementation and multi-micronutrient tablet). Using a Markov state transition model we simulated TB incidence, treatment, and TB-attributable mortality among household contacts receiving the RATIONS intervention, as compared to no nutritional support. We calculated health outcomes (TB cases, TB deaths, and disability-adjusted life years [DALYs]) over the lifetime of intervention recipients and assessed costs from government and societal perspectives. We tested the robustness of results to parameter changes via deterministic and probabilistic sensitivity analysis.

Findings

Over two years, household contacts receiving the RATIONS intervention would experience 39% (95% uncertainty interval (UI): 23-52) fewer TB cases and 59% (95% UI: 44-69) fewer TB deaths. The intervention was estimated to avert 13,775 (95% UI: 9036-20,199) TB DALYs over the lifetime of the study cohort comprising 100,000 household contacts and was cost-effective from both government (incremental cost-effectiveness ratio: $229 per DALY averted [95% UI: 133-387]) and societal perspectives ($184 per DALY averted [95% UI: 83-344]). The results were most sensitive to the cost of the nutritional supplement.

Interpretation

Prompt nutritional support for household contacts of persons with TB disease would be cost-effective in reducing TB incidence and mortality in India.

Summary

Undernutrition is the leading cause of tuberculosis in India. Using a Markov state-transition model, we found that food baskets for household contacts of persons with tuberculosis would be cost-effective in reducing tuberculosis incidence and mortality in India.

Research in context

Evidence before this study: Undernutrition is the leading risk factor for TB worldwide. Recently, the RATIONS study demonstrated a roughly 40% reduction in incident TB among household contacts who received in-kind macronutrient and micronutrient supplementation. Added value of this study: Although the RATIONS study demonstrated a dramatic reduction in incident TB, it is unclear if nutritional interventions to prevent TB are cost-effective. Previously, only one cost-effectiveness analysis of nutritional interventions for household contacts has been published. Due to lack of published data, that study had to make assumptions regarding the impact of nutritional interventions on TB incidence and mortality. In this study, we conducted an economic evaluation of a RATIONS-style intervention to reduce incident TB and mortality in India using observed data. Implications of all the available evidence: In-kind nutritional supplementation for household contacts of individuals with TB disease would be cost-effective in reducing incident TB and TB mortality, particularly if TB programs leverage economies of scale to bring down the cost of the nutritional intervention.

Diagnosis and Management of Latent Tuberculosis Infection: Updates

India has the largest problem of tuberculosis (TB) infection globally (estimated at about 35-40 crores cases), and around 18-36 lakh develop active tuberculosis annually. Latent TB is defined as a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens with no evidence of clinically manifested active TB. The progression of a latent infection to active tuberculosis increases several-fold in children < 5 years of age and in people with some or the other form of an immunocompromising condition. Therefore, to cater to this gigantic problem of tuberculosis, it is necessary to have awareness about latent tuberculosis infection (LTBI) amongst clinicians and to prioritise its diagnosis and treatment in high-risk groups. India plans to end TB well before the deadline set by the World Health organisation (WHO). However, this can only be achieved with effective strategies targeting LTBI. Multiple treatment regimens have been approved for LTBI treatment, and all have comparable efficacy. The selection of one regimen over the other depends on various factors, such as availability, risk of adverse events, age, and drug interactions. Recently, the WHO, as well as the Revised National TB Control Programme (RNTCP), have updated their guidelines on TB preventive treatment in 2020 and 2021, respectively. This review has been especially prepared to acknowledge the differences in approach to LTBI in developed and developing countries.

Prevalence and predictors of tuberculosis infection among people living with HIV in a high tuberculosis burden context

BACKGROUND

Tuberculosis (TB) disease is the leading cause of mortality among people living with HIV (PLHIV). Interferon-gamma release assays (IGRAs) are approved for TB infection ascertainment. However, current IGRA data on the prevalence of TB infection in the context of near-universal access to antiretroviral therapy (ART) and TB preventive therapy (TPT) are lacking. We estimated the prevalence and determinants of TB infection among PLHIV within a high TB and HIV burden context.

METHODS

This cross-sectional study included data from adult PLHIV age ≥18 years in whom QuantiFERON-TB Gold Plus (QFT-Plus) assay, an IGRA, was performed. TB infection was defined as a positive or indeterminate QFT-Plus test. Participants with TB and those who had previously used TPT were excluded. Regression analysis was performed to identify independent predictors of TB infection.

RESULTS

Of 121 PLHIV with QFT-Plus test results, females were 74.4% (90/121), and the mean age was 38.4 (SD 10.8) years. Overall, 47.9% (58/121) were classified as TB infection (QFT-Plus test positive and indeterminate results were 39.7% (48/121) and 8.3% (10/121), respectively). Being obese/overweight (body mass index ≥25 kg/m²; p=0.013, adjusted OR (aOR) 2.90, 95% CI 1.25 to 6.74) and ART usage for >3 years (p=0.013, aOR 3.99, 95% CI 1.55 to 10.28) were independently associated with TB infection.

CONCLUSION

There was a high TB infection prevalence among PLHIV. A longer period of ART and obesity were independently associated with TB infection. The relationship between obesity/overweight and TB infection may be related to ART use and immune reconstitution and requires further investigation. Given the known benefit of test-directed TPT among PLHIV never exposed to TPT, its clinical and cost implications for low and middle-income countries should be explored further.

Efficacy, safety, and tolerability of isoniazid preventive therapy for tuberculosis in people living with HIV

OBJECTIVE

The aim of this study was to systematically assess the efficacy, safety, and tolerability of isoniazid preventive therapy (IPT) for tuberculosis (TB) in people with HIV (PWH).

DESIGN

A systematic review and meta-analysis.

METHODS

A thorough literature search was performed using PubMed, Cochrane CENTRAL, and Google Scholar from their inception to June 30, 2021. All randomized controlled trials (RCTs) investigating the efficacy, safety, or tolerability of IPT on PWH compared with placebo or active comparators were included in the study. The heterogeneity among the studies was identified by using the I2 statistic and Cochran's Q test.

RESULTS

Out of the 924 nonduplicate RCTs identified through database searching and other sources, 26 studies comprising 38 005 patients were included. The overall effect estimate identified the reduction of active TB incidence [odds ratio (OR) 0.69; 95% confidence interval (95% CI) 0.57-0.84; P  < 0.001], but not all-cause mortality (OR 0.91; 95% CI 0.82, 1.02; P  = 0.10) with IPT compared with the control. In addition, no significant association was identified between the use of IPT and the risk of peripheral neuropathy (OR 1.50; 95% CI 0.96-2.36; P  = 0.08) and hepatotoxicity (OR 1.21; 95% CI 0.97-1.52; P  = 0.09).

CONCLUSION

This systematic review and meta-analysis identified a significant reduction in the incidence of active TB, but not all-cause mortality, among PWH who received IPT compared with the control. Lesser number of outcomes may be the reason for nonsignificant results in terms of safety outcomes of IPT. Therefore, there is a need for extensive and long-term studies to address these issues further, especially in TB/HIV endemic areas.

Comprehensive league table of cost-utility ratios: A systematic review of cost-effectiveness evidence for health policy decisions in India

Background and objectives

Although a relatively recent concept for developing countries, the developed world has been using League Tables as a policy guiding tool for a comprehensive assessment of health expenditures; country-specific "League tables" can be a very useful tool for national healthcare planning and budgeting. Presented herewith is a comprehensive league table of cost per Quality Adjusted Life Years (QALY) or Disability Adjusted Life Years (DALY) ratios derived from Health Technology Assessment (HTA) or economic evaluation studies reported from India through a systematic review.

Methods

Economic evaluations and HTAs published from January 2003 to October 2019 were searched from various databases. We only included the studies reporting common outcomes (QALY/DALY) and methodology to increase the generalizability of league table findings. To opt for a uniform criterion, a reference case approach developed by Health Technology Assessment in India (HTAIn) was used for the reporting of the incremental cost-effectiveness ratio. However, as, most of the articles expressed the outcome as DALY, both (QALY and DALY) were used as outcome indicators for this review.

Results

After the initial screening of 9,823 articles, 79 articles meeting the inclusion criteria were selected for the League table preparation. The spectrum of intervention was dominated by innovations for infectious diseases (33%), closely followed by maternal and child health (29%), and non-communicable diseases (20%). The remaining 18% of the interventions were on other groups of health issues, such as injuries, snake bites, and epilepsy. Most of the interventions (70%) reported DALY as an outcome indicator, and the rest (30%) reported QALY. Outcome and cost were discounted at the rate of 3 by 73% of the studies, at 5 by 4% of the studies, whereas 23% of the studies did not discount it. Budget impact and sensitivity analysis were reported by 18 and 73% of the studies, respectively.

Interpretation and conclusions

The present review offers a reasonably coherent league table that reflects ICER values of a range of health conditions in India. It presents an update for decision-makers for making decisions about resource allocation.

Nutritional Supplementation Would Be Cost-Effective for Reducing Tuberculosis Incidence and Mortality in India: The Ration Optimization to Impede Tuberculosis (ROTI-TB) Model

BACKGROUND

Undernutrition is the leading cause of tuberculosis (TB) in India and is associated with increased TB mortality. Undernutrition also decreases quality of life and economic productivity.

METHODS

We assessed the cost-effectiveness of providing augmented rations to undernourished Indians through the government's Targeted Public Distribution System (TPDS). We used Markov state transition models to simulate disease progression and mortality among undernourished individuals in 3 groups: general population, household contacts (HHCs) of people living with TB, and persons living with human immunodeficiency virus (HIV). The models calculate costs and outcomes (TB cases, TB deaths, and disability-adjusted life years [DALYs]) associated with a 2600 kcal/day diet for adults with body mass index (BMI) of 16-18.4 kg/m2 until they attain a BMI of 20 kg/m2 compared to a status quo scenario wherein TPDS rations are unchanged. We employed deterministic and probabilistic sensitivity analyses to test result robustness.

RESULTS

Over 5 years, augmented rations could avert 81% of TB cases and 88% of TB deaths among currently undernourished Indians. Correspondingly, this intervention could forestall 78% and 48% of TB cases and prevent 88% and 70% of deaths among undernourished HHCs and persons with HIV, respectively. Augmented rations resulted in 10-fold higher resolution of undernutrition and were highly cost-effective with (incremental cost-effectiveness ratio [ICER] of $470/DALY averted). ICER was lower for HHCs ($360/DALY averted) and the HIV population ($250/DALY averted).

CONCLUSIONS

A robust nutritional intervention would be highly cost-effective in reducing TB incidence and mortality while reducing chronic undernutrition in India.

The impact of blood transcriptomic biomarker targeted tuberculosis preventive therapy in people living with HIV: a mathematical modelling study

BACKGROUND

Tuberculosis (TB) preventive therapy is recommended for all people living with HIV (PLHIV). Despite the elevated risk of TB amongst PLHIV, most of those eligible for preventive therapy would never develop TB. Tests which can identify individuals at greatest risk of disease would allow more efficient targeting of preventive therapy.

METHODS

We used mathematical modelling to estimate the potential impact of using a blood transcriptomic biomarker (RISK11) to target preventive therapy amongst PLHIV. We compared universal treatment to RISK11 targeted treatment and explored the effect of repeat screening of the population with RISK11.

RESULTS

Annual RISK11 screening, with preventive therapy provided to those testing positive, could avert 26% (95% CI 13-34) more cases over 10 years compared to one round of universal treatment. For the cost per case averted to be lower than universal treatment, the maximum cost of the RISK11 test was approximately 10% of the cost of preventive therapy. The benefit of RISK11 screening may be greatest amongst PLHIV on ART (compared to ART naïve individuals) due to the increased specificity of the test in this group.

CONCLUSIONS

Biomarker targeted preventive therapy may be more effective than universal treatment amongst PLHIV in high incidence settings but would require repeat screening.

Economic and modeling evidence for tuberculosis preventive therapy among people living with HIV: A systematic review and meta-analysis

BACKGROUND

Human immunodeficiency virus (HIV) is the strongest known risk factor for tuberculosis (TB) through its impairment of T-cell immunity. Tuberculosis preventive treatment (TPT) is recommended for people living with HIV (PLHIV) by the World Health Organization, as it significantly reduces the risk of developing TB disease. We conducted a systematic review and meta-analysis of modeling studies to summarize projected costs, risks, benefits, and impacts of TPT use among PLHIV on TB-related outcomes.

METHODS AND FINDINGS

We searched MEDLINE, Embase, and Web of Science from inception until December 31, 2020. Two reviewers independently screened titles, abstracts, and full texts; extracted data; and assessed quality. Extracted data were summarized using descriptive analysis. We performed quantile regression and random effects meta-analysis to describe trends in cost, effectiveness, and cost-effectiveness outcomes across studies and identified key determinants of these outcomes. Our search identified 6,615 titles; 61 full texts were included in the final review. Of the 61 included studies, 31 reported both cost and effectiveness outcomes. A total of 41 were set in low- and middle-income countries (LMICs), while 12 were set in high-income countries (HICs); 2 were set in both. Most studies considered isoniazid (INH)-based regimens 6 to 2 months long (n = 45), or longer than 12 months (n = 11). Model parameters and assumptions varied widely between studies. Despite this, all studies found that providing TPT to PLHIV was predicted to be effective at averting TB disease. No TPT regimen was substantially more effective at averting TB disease than any other. The cost of providing TPT and subsequent downstream costs (e.g. post-TPT health systems costs) were estimated to be less than $1,500 (2020 USD) per person in 85% of studies that reported cost outcomes (n = 36), regardless of study setting. All cost-effectiveness analyses concluded that providing TPT to PLHIV was potentially cost-effective compared to not providing TPT. In quantitative analyses, country income classification, consideration of antiretroviral therapy (ART) use, and TPT regimen use significantly impacted cost-effectiveness. Studies evaluating TPT in HICs suggested that TPT may be more effective at preventing TB disease than studies evaluating TPT in LMICs; pooled incremental net monetary benefit, given a willingness-to-pay threshold of country-level per capita gross domestic product (GDP), was $271 in LMICs (95% confidence interval [CI] -$81 to $622, p = 0.12) and was $2,568 in HICs (-$32,115 to $37,251, p = 0.52). Similarly, TPT appeared to be more effective at averting TB disease in HICs; pooled percent reduction in active TB incidence was 20% (13% to 27%, p < 0.001) in LMICs and 37% (-34% to 100%, p = 0.13) in HICs. Key limitations of this review included the heterogeneity of input parameters and assumptions from included studies, which limited pooling of effect estimates, inconsistent reporting of model parameters, which limited sample sizes of quantitative analyses, and database bias toward English publications.

CONCLUSIONS

The body of literature related to modeling TPT among PLHIV is large and heterogeneous, making comparisons across studies difficult. Despite this variability, all studies in all settings concluded that providing TPT to PLHIV is potentially effective and cost-effective for preventing TB disease.

The paradigm shift in the approach to management of latent tuberculosis infection in high tuberculosis burden countries

Introduction: Addressing the reservoir of Latent Tuberculosis Infection (LTBI) is critical to TB elimination because if left untreated LTBI can progress to active TB disease. This additional burden can prevent achieving the global targets of TB elimination. Management of LTBI has been a low priority target for National TB Elimination Programs (NTEP) due to various challenges in the field settings.Areas covered: This article reviews the most recent advances in the field of LTBI management including newer diagnostics, treatments, vaccines, programmatic challenges, and gaps and suggests a way forward that can be adopted by NTEPs for LTBI. We searched the electronic databases of PubMed, Scopus, and Web of Science for studies published between 2010 to 2020 using MeSH terms: Latent TB Diagnosis, TB preventive therapy, Vaccines, LTBI, and HIV/ COVID.Expert opinion: NTEPs of developing countries should offer a better, point-of-care diagnostic, and effective treatment for LTBI to reduce the number of new TB cases arising from people infected with M.tb. Awareness about LTBI should be increased among the health system staff and the public. More funding is needed to advance research as well as implement the newer findings in the NTEP to achieve the End TB targets by 2035.

Cost-effectiveness of scaling up short course preventive therapy for tuberculosis among children across 12 countries

BACKGROUND

While household contact investigation is widely recommended as a means to reduce the burden of tuberculosis (TB) among children, only 27% of eligible pediatric household contacts globally received preventive treatment in 2018. We assessed the cost-effectiveness of household contact investigation for TB treatment and short-course preventive therapy provision for children under 15 years old across 12 high TB burden countries.

METHODS

We used decision analysis to compare the costs and estimated effectiveness of three intervention scenarios: (a) status quo (existing levels of coverage with isoniazid preventive therapy), (b) contact investigation with treatment of active TB but no additional preventive therapy, and (c) contact investigation with TB treatment and provision of short-course preventive therapy. Using country-specific demographic, epidemiological and cost data from the literature, we estimated annual costs (in 2018 USD) and the number of TB cases and deaths averted across 12 countries. Incremental cost effectiveness ratios were assessed as cost per death and per disability-adjusted life year [DALY] averted.

FINDINGS

Our model estimates that contact investigation with treatment of active TB and provision of preventive therapy could be highly cost-effective compared to the status quo (ranging from $100 per DALY averted in Malawi to $1,600 in Brazil; weighted average $383 per DALY averted [uncertainty range: $248 - $1,130]) and preferred to contact investigation without preventive therapy (weighted average $751 per DALY averted [uncertainty range: $250 - $1,306]). Key drivers of cost-effectiveness were TB prevalence, sensitivity of TB diagnosis, case fatality for untreated TB, and cost of household screening.

INTERPRETATION

Based on this modeling analysis of available published data, household contact investigation with provision of short-course preventive therapy for TB has a value-for-money profile that compares favorably with other interventions.

FUNDING

Unitaid (2017-20-IMPAACT4TB).

Cost-effectiveness of universal isoniazid preventive therapy among HIV-infected pregnant women in South Africa

OBJECTIVE

To estimate the incremental cost-effectiveness of universal vs. test-directed treatment of latent tuberculous infection (LTBI) among human immunodeficiency virus (HIV) positive pregnant women in South Africa.

METHODS

We compared tuberculin skin test (TST) directed isoniazid preventive therapy (IPT) (TST placement with delivery of IPT to women with positive results) against QuantiFERON^®-TB Gold In-Tube (QGIT) directed IPT and universal IPT using decision analysis. Costs were measured empirically in six primary care public health clinics in Matlosana, South Africa. The primary outcome was the incremental cost-effectiveness ratio, expressed in 2016 US$ per disability-adjusted life-year (DALY) averted.

RESULTS

We estimated that 29.2 of every 1000 pregnant women would develop TB over the course of 1 year in the absence of IPT. TST-directed IPT reduced this number to 24.5 vs. 22.6 with QGIT-directed IPT and 21.0 with universal IPT. Universal IPT was estimated to cost $640/DALY averted (95% uncertainty range $44-$3146) relative to TST-directed IPT and was less costly and more effective (i.e., dominant) than QGIT-directed IPT. Cost-effectiveness was most sensitive to the probability of developing TB and LTBI prevalence.

CONCLUSION

Providing IPT to all eligible women can be a cost-effective strategy to prevent TB among HIV-positive pregnant women in South Africa.

Brief Report: High Programmatic Isoniazid Preventive Therapy (IPT) Use in Pregnancy Among HIV-Infected Women

BACKGROUND

The World Health Organization recommends isoniazid preventive therapy (IPT) for people living with HIV (PLHIV) to prevent tuberculosis (TB), including pregnant women. Recent trial results suggest increased adverse pregnancy outcomes associated with IPT during pregnancy. Data are limited regarding programmatic IPT use in pregnant PLHIV.

METHODS

We assessed previous programmatic IPT during pregnancy among HIV-infected mothers on enrollment to an infant TB prevention trial in Kenya. Pregnancy IPT use was assessed by the estimated conception date assuming 38 weeks of gestation. Correlates of initiation and completion were analyzed by relative risk regression, using generalized linear models with log link and Poisson family adjusted for IPT initiation year.

RESULTS

Between August 15, 2016, to June 6, 2018, 300 HIV-infected women enrolled at 6 weeks postpartum. Two hundred twenty-four (74.7%) women reported previous IPT, of whom 155/224 (69.2%) had any pregnancy IPT use. Forty-five (29.0%) initiated preconception extending into early pregnancy, 41 (26.5%) initiated and completed during pregnancy, and 69 (44.5%) initiated in pregnancy and extended into early postpartum. The median gestational age at IPT pregnancy initiation was 15.1 weeks (interquartile range 8.3-28.4). Pregnancy/early postpartum IPT initiation was associated with new pregnancy HIV diagnosis [adjusted relative risk 1.9 95% confidence interval (CI): 1.6 to 2.2, P < 0.001]. Six-month IPT completion rates were high [147/160 (91.9%)] among women with sufficient time to complete before trial enrollment and similar among preconception or during pregnancy initiators [adjusted relative risk 0.93 (95% confidence interval: 0.83 to 1.04, P = 0.19)].

CONCLUSIONS

Programmatic IPT use was high in pregnant PLHIV, with frequent periconception and early pregnancy initiation. Programmatic surveillance could provide further insights on pregnancy IPT implementation and maternal and infant safety outcomes.

Assessing frontline HIV service provider efficiency using data envelopment analysis: a case study of Philippine social hygiene clinics (SHCs)

BACKGROUND

Globally, local and frontline HIV service delivery units have been deployed to halt the HIV epidemic. However, with the limited resources, there is a need to understand how these units can deliver their optimum outputs/outcomes efficiently given the inputs. This study aims to determine the efficiency of the social hygiene clinics (SHC) in the Philippines as well as to determine the association of the meta-predictor to the efficiencies.

METHODS

In determining efficiency, we used the variables from two data sources namely the 2012 Philippine HIV Costing study and 2011 Integrated HIV Behavioral and Serologic Surveillance, as inputs and outputs, respectively. Various data management protocols and initial assumptions in data matching, imputation and variable selection, were used to create the final dataset with 9 SHCs. We used data envelopment analysis (DEA) to analyse the efficiency, while variations in efficiencies were analysed using Tobit regression with area-specific meta-predictors.

RESULTS

There were potentially inefficient use of limited resources among sampled SHC in both aggregate and key populations. Tobit regression results indicated that income was positively associated with efficiency, while HIV prevalence was negatively associated with the efficiency variations among the SHCs.

CONCLUSIONS

We were able to determine the inefficiently performing SHCs in the Philippines. Though currently inefficient, these SHCs may adjust their inputs and outputs to become efficient in the future. While there were indications of income and HIV prevalence to be associated with the efficiency variations, the results of this case study may only be limited in generalisability, thus further studies are warranted.

Current trends and intricacies in the management of HIV-associated pulmonary tuberculosis

Human immunodeficiency virus (HIV) epidemic has undoubtedly increased the incidence of tuberculosis (TB) globally, posing a formidable global health challenge affecting 1.2 million cases. Pulmonary TB assumes utmost significance in the programmatic perspective as it is readily transmissible as well as easily diagnosable. HIV complicates every aspect of pulmonary tuberculosis from diagnosis to treatment, demanding a different approach to effectively tackle both the diseases. In order to control these converging epidemics, it is important to diagnose early, initiate appropriate therapy for both infections, prevent transmission and administer preventive therapy. Liquid culture methods and nucleic acid amplification tests for TB confirmation have replaced conventional solid media, enabling quicker and simultaneous detection of mycobacterium and its drug sensitivity profile Unique problems posed by the syndemic include Acquired rifampicin resistance, drug-drug interactions, malabsorption of drugs and immune reconstitution inflammatory syndrome or paradoxical reaction that complicate dual and concomitant therapy. While the antiretroviral therapy armamentarium is constantly reinforced by discovery of newer and safer drugs every year, only a few drugs for anti tuberculosis treatment have successfully emerged. These include bedaquiline, delamanid and pretomanid which have entered phase III B trials and are also available through conditional access national programmes. The current guidelines by WHO to start Antiretroviral therapy irrespective of CD4+ cell count based on benefits cited by recent trials could go a long way in preventing various complications caused by the deadly duo. This review provides a consolidated gist of the advancements, concepts and updates that have emerged in the management of HIV-associated pulmonary TB for maximizing efficacy, offering latest solutions for tackling drug-drug interactions and remedial measures for immune reconstitution inflammatory syndrome.