Modeling the Cost-Effectiveness of Latent Tuberculosis Screening and Treatment Strategies in Recent Migrants to a Low-Incidence Setting.

Many tuberculosis (TB) cases in low-incidence settings are attributed to reactivation of latent TB infection (LTBI) acquired overseas. We assessed the cost-effectiveness of community-based LTBI screening and treatment strategies in recent migrants to a low-incidence setting (Australia). A decision-analytical Markov model was developed that cycled 1 migrant cohort (≥11-year-olds) annually over a lifetime from 2020. Postmigration/onshore and offshore (screening during visa application) strategies were compared with existing policy (chest x-ray during visa application). Outcomes included TB cases averted and discounted cost per quality-adjusted life-year (QALY) gained from a health-sector perspective. Most recent migrants are young adults and cost-effectiveness is limited by their relatively low LTBI prevalence, low TB mortality risks, and high emigration probability. Onshore strategies cost at least $203,188 (Australian) per QALY gained, preventing approximately 2.3%-7.0% of TB cases in the cohort. Offshore strategies (screening costs incurred by migrants) cost at least $13,907 per QALY gained, preventing 5.5%-16.9% of cases. Findings were most sensitive to the LTBI treatment quality-of-life decrement (further to severe adverse events); with a minimal decrement, all strategies caused more ill health than they prevented. Additional LTBI strategies in recent migrants could only marginally contribute to TB elimination and are unlikely to be cost-effective unless screening costs are borne by migrants and potential LTBI treatment quality-of-life decrements are ignored.

Comparing the cost-effectiveness of two screening strategies for latent tuberculosis infection in Portugal.

INTRODUCTION AND OBJECTIVES: Screening for latent tuberculosis infection (LTBI) in close contacts of infectious TB cases might include Tuberculin Skin Test (TST) and Interferon-Gamma Release Assays (IGRA), in combination or as single-tests. In Portugal, the screening strategy changed from TST followed by IGRA to IGRA-only testing in 2016. Our objective was to compare the cost-effectiveness of two-step TST/IGRA with the current IGRA-only screening strategy in immunocompetent individuals exposed to individuals with respiratory TB. MATERIALS AND METHODS: We reviewed clinical records of individuals exposed to infectious TB cases diagnosed in 2015 and 2016, in two TB outpatient centers in the district of Porto. We estimated medical, non-medical and indirect costs for each screening strategy, taking into account costs of tests and health care personnel, travel distance from place of residence to screening site and employment status. We calculated the incremental cost-effectiveness ratio (ICER) as the cost difference between the two screening strategies with the difference number of LTBI diagnosis as a measure of cost-effectiveness, assuming that treating LTBI is a cost-effective intervention. We also calculated adjusted odds-ratios to test the association between diagnosis of LTBI and screening strategy and estimated the total cost for averting a potential TB case. RESULTS: We compared 499 contacts TST/IGRA screened with 547 IGRA-only. IGRA-only strategy yielded a higher screening effectiveness for diagnosing latent tuberculosis infection (aOR 2.12, 95%CI: 1.53 - 2.94). ICER was €106 per LTBI diagnosis, representing increased effectiveness with a slightly increased cost of IGRA-only screening strategy. CONCLUSIONS: Our data suggests that in Portugal LTBI screening with IGRA-only is more cost-effective than the two-step TST/IGRA testing strategy, preventing a higher number of cases of TB cases.

Cost-effectiveness of IGRA/QFT-Plus for TB screening of migrants in Oman.

OBJECTIVE: To estimate the cost of a screening program for identifying latent tuberculosis (TB) infections in migrants to Oman. METHODS: A Markov model was used to estimate the cost of screening using an interferon-gamma release assay (IGRA) applied to all migrants from high TB endemic countries, followed by preventive TB treatment. RESULTS: The model compared seven different scenarios, with a comparison of the direct cost and the quality-adjusted life-years (QALYs) saved. CONCLUSIONS: IGRA testing followed by 3 months of preventive treatment with rifapentine/isoniazid (3HP) was the most cost-effective intervention.

Estimates of Testing for Latent Tuberculosis Infection and Cost, United States, 2013.

OBJECTIVES: Tracking trends in the testing of latent tuberculosis infection (LTBI) can help measure tuberculosis elimination efforts in the United States. The objectives of this study were to estimate (1) the annual number of persons tested for LTBI and the number of LTBI tests conducted, by type of test and by public, private, and military sectors, and (2) the cost of LTBI testing in the United States. METHODS: We searched the biomedical literature for published data on private-sector and military LTBI testing in 2013, and we used back-calculation to estimate public-sector LTBI testing. To estimate costs, we applied Medicare-allowable reimbursements in 2013 by test type. RESULTS: We estimated an average (low-high) 13.3 million (11.3-15.4 million) persons tested for LTBI and 15.3 million (12.9-17.7 million) LTBI tests, of which 13.2 million (11.1-15.3 million) were tuberculin skin tests and 2.1 million (1.8-2.4 million) were interferon-γ release assays (IGRAs). Eighty percent of persons tested were in the public sector, 18% were in the private sector, and 2% were in the military. Costs of LTBI tests and of chest radiography totaled $314 million (range, $256 million to $403 million). CONCLUSIONS: To achieve tuberculosis elimination, millions more persons will need to be tested in all sectors. By targeting testing to only those at high risk of tuberculosis and by using more specific IGRA tests, the incidence of tuberculosis in the United States can be reduced and resources can be more efficiently used.

Cost-effectiveness of tuberculosis screening for migrant children in a low-incidence country.

Detection of latent tuberculous infection (LTBI) is important to prevent progression to active tuberculosis (TB), particularly in migrant children. We evaluated the cost-effectiveness of TB screening in migrant children in a low-incidence country. Retrospective analysis of a school-based TB screening programme in Switzerland. Migrant children were screened using the tuberculin skin test (TST). TST was considered positive if induration was 10 mm in non-bacille Calmette-Guérin (BCG) vaccinated children, and 15 mm in BCG-vaccinated children. Screening and treatment costs were extracted from hospital records. Cost impact was analysed as the difference between the cost of treatment for active TB and screening plus LTBI treatment. Cost per disability-adjusted life-years (DALY) was assessed based on Global Burden of Disease disability weight estimates. Of 1462 children screened, 1120 (77%; mean age 10.9 years; 46% female) underwent a TST. TST induration of 10 mm was documented in 78 (6.9%), and TST induration of 15 mm in 19 (1.6%). Twenty-one were TST-positive, and 17 children were diagnosed with LTBI; none had active TB. The highest rates of TST induration 10 mm were found in migrant children from Africa (16.6%) and Turkey (15.4%). Screening for LTBI was cost-effective if LTBI prevalence was 14%, with a progression rate of 5%; in case of lower LTBI prevalence, LTBI screening is cost-effective if progression rates to active TB are higher. School-based TB screening programmes targeting migrant children are cost-effective if populations with a relatively increased LTBI prevalence and/or high progression rates are included. .

A screening strategy for latent tuberculosis in healthcare workers: Cost-effectiveness and budget impact of universal versus targeted screening.

OBJECTIVE: To evaluate the clinical, cost-efficiency, and budgetary implications of universal versus targeted latent tuberculosis infection (LTBI) screening strategies among healthcare workers (HCWs) in an intermediate tuberculosis (TB)-burden country. DESIGN: Pragmatic cost-effectiveness and budget impact analysis using decision-analytic modeling. SETTING: A tertiary-care hospital in Singapore. METHODS: We compared 7 potentially implementable LTBI screening programs including universal and targeted strategies with different screening frequencies. Feasible targeting methods included stratification by country of origin (a proxy for risk of prior TB exposure) and by high-risk occupation. The clinical and financial consequences of each strategy were estimated relative to "no screening" (current practice) and compared to locally appropriate cost-effectiveness thresholds. All analyses were conducted from the hospital's perspective over a 3-year time horizon, based on the typical hospital planning period. Parameter uncertainties were accounted for using sensitivity analyses. RESULTS: In our model, relative to current practice, screening new international hires and triennial screening of existing high-risk workers is most cost-effective (US$58 per quality adjusted life year [QALY]) and decreases active TB cases from 19 to 14. Screening all new hires combined with triennial universal screening, with or without annual high-risk screening or annual universal screening, reduced active TB to a range of 19 to 6 cases, but these strategies are less cost-effective and require substantially higher expenditures. CONCLUSIONS: Targeted LTBI screening for HCWs can be highly cost-effective for hospitals in settings similar to Singapore. More inclusive screening strategies (including regular universal screening) can yield better outcomes but are less efficient and may even be unaffordable.

A situational analysis of latent tuberculosis infection among incarcerated population in Japan.

BACKGROUND: The World Health Organization recommends that systematic testing and screening of latent tuberculosis infection (LTBI) among the incarcerated population "should be considered", though based on evidence of either low or very low quality. However, in Japan, a TB middle-burden country, systematic screening for LTBI in correctional facilities is currently not conducted. As part of a larger study to determine the cost-effectiveness of LTBI screening in correctional facilities in Japan, this study was conducted to determine the situation of LTBI, including treatment outcome, among the incarcerated population in Japan, and provide the essential data for cost-effectiveness analysis. METHOD: A cross-sectional study was conducted between 2017 and 2018 with public health centers which have one or more correctional facilities under their jurisdiction. Questionnaire surveys were sent to collect information on their policy of managing LTBI patients notified from correctional facilities, including whether or not there was a standardized procedure for initiating LTBI treatment, and also to collect sociodemographic information and treatment outcome of LTBI patients who were notified from the respective correctional facilities in 2015 and 2016. RESULTS: The survey was sent to a total of 163 public health centers, out of which 133 (81.6%) responded. 8 of the 133 public health centers actively guided the correctional facilities regarding LTBI treatment initiation through a standardized procedure, while 115 either had not established such procedure or were unaware of how LTBI treatment was being initiated in the correctional facilities. A total of 91 LTBI patients were notified from the correctional facilities in 2015 and 2016, and the information of 89 were available for analysis. 82 were males, and 83 were Japan-born. Treatment outcome was known for 88 patients, of which 70 had completed treatment. Of the 18 who did not complete the treatment, 15 had been lost to follow-up upon release from the facilities. Among those who had been released whilst on treatment, the proportion of those who completed the treatment was higher in those patients who received pre-release visit by a public health nurse, than those who did not. CONCLUSIONS: LTBI treatment was often being initiated without consideration for the patients' prison term. The treatment completion rate within jail was high, indicating the possibility that incarcerated population can benefit for LTBI treatment. On the other hand, the completion rate decreased significantly among those who had been released while still on treatment. In order to optimize the benefit, initiation of LTBI must carefully be considered upon the patient's prison term, as well as coordination among the relevant organizations to ensure continuity of care after release.

Cost-effectiveness of contact screening strategies for tuberculosis among high-school adolescents in South Korea.

BACKGROUND: Effective latent tuberculous infection (LTBI) control among adolescents is a critical component of tuberculosis (TB) elimination in Korea. OBJECTIVE: To compare the cost-effectiveness of the following contact screening strategies for LTBI among high-school adolescents after TB outbreaks: QuantiFERON®-TB Gold In-Tube (QFT-GIT), the tuberculin skin test (TST), or TST/QFT-GIT (two-step strategy). METHOD: The costs of post-TB outbreak screening strategies were calculated using a mixed (top-down and bottom-up) cost analysis method and expressed in 2015 US dollars. Cost-effectiveness was evaluated using a decision analysis model from the health system perspective, comparing cumulative health care costs and the total number of TB cases averted. RESULTS: In a hypothetical cohort of 1000 students, screening using the TST-alone strategy averted 1.6 TB cases at a total cost of US$52 566. The QFT-GIT-alone strategy helped avert 2.0 TB cases, but was associated with a much higher total cost (US$108 435), resulting in an incremental cost-effectiveness ratio of US$140 933/TB case averted. The two-step TST/QFT-GIT strategy was worse than the TST-alone strategy, averting 1.3 TB cases at US$75 267. CONCLUSION: The TST-alone strategy was the most cost-effective; the QFT-GIT-alone strategy averted the greatest number of TB cases but incurred the highest cost in contact investigation for school TB outbreaks.

The effectiveness and cost-effectiveness of screening for latent tuberculosis among migrants in the EU/EEA: a systematic review.

BackgroundMigrants account for a large and growing proportion of tuberculosis (TB) cases in low-incidence countries in the European Union/European Economic Area (EU/EEA) which are primarily due to reactivation of latent TB infection (LTBI). Addressing LTBI among migrants will be critical to achieve TB elimination. Methods: We conducted a systematic review to determine effectiveness (performance of diagnostic tests, efficacy of treatment, uptake and completion of screening and treatment) and a second systematic review on cost-effectiveness of LTBI screening programmes for migrants living in the EU/EEA. Results: We identified seven systematic reviews and 16 individual studies that addressed our aims. Tuberculin skin tests and interferon gamma release assays had high sensitivity (79%) but when positive, both tests poorly predicted the development of active TB (incidence rate ratio: 2.07 and 2.40, respectively). Different LTBI treatment regimens had low to moderate efficacy but were equivalent in preventing active TB. Rifampicin-based regimens may be preferred because of lower hepatotoxicity (risk ratio = 0.15) and higher completion rates (82% vs 69%) compared with isoniazid. Only 14.3% of migrants eligible for screening completed treatment because of losses along all steps of the LTBI care cascade. Limited economic analyses suggest that the most cost-effective approach may be targeting young migrants from high TB incidence countries. Discussion: The effectiveness of LTBI programmes is limited by the large pool of migrants with LTBI, poorly predictive tests, long treatments and a weak care cascade. Targeted LTBI programmes that ensure high screening uptake and treatment completion will have greatest individual and public health benefit.

Economic burden of HIV and TB/HIV coinfection in a middle-income country: a costing analysis alongside a pragmatic clinical trial in Brazil.

OBJECTIVE: The objective of this study was to measure the costs of people living with HIV (PLHIV) as well as active tuberculosis (TB/HIV), latent tuberculosis infection (LTBI/HIV) or without TB (HIV/AIDS). METHODS: We analysed the costs through the entire pathway of care during the prediagnosis and treatment periods from the Brazilian public health system perspective. We applied a combination of bottom-up and top-down approaches to capture and estimate direct medical and non-medical costs. We measured the mean cost per patient per type of care (inpatient, outpatient and emergency care) and disease category (HIV/AIDS, HIV/AIDS death, TB/HIV, TB/HIV death and LTBI/HIV). RESULTS: Between March 2014 and March 2016 we recruited 239 PLHIV. During the follow-up 26 patients were diagnosed and treated for TB and 5 received chemoprophylaxis for LTBI. During the prediagnosis and treatment period, the mean total costs for HIV or AIDS and AIDS death categories were US$1558 and US$2828, respectively. The mean total costs for TB/HIV and TB/HIV death categories were US$5289.0 and US$8281, respectively. The mean total cost for the LTBI/HIV category was US$882. CONCLUSIONS: Patients with TB/HIV impose a higher economic burden on the health system than HIV/AIDS and LTBI/HIV. Patients with LTBI/HIV were the lowest cost group among all disease categories, indicating that preventive TB treatment can avoid the further costs treating active TB. TRIAL REGISTRATION NUMBER: RBR-22t943, Results.

Cost-effectiveness analysis of strategies using new immunological diagnostic tests of latent tuberculosis infection before TNF-blockers therapy.

Several tests have been proposed to detect latent tuberculosis (LTB). OBJECTIVE: To evaluate the cost-effectiveness of different interferon-gamma release assays based strategies used to screen LTB before tumour necrosis factor (TNF) blockers initiation. METHODS: Consecutive patients with rheumatoid arthritis, spondyloarthritis or Crohn's disease for whom TNF-blockers were considered, were recruited in 15 tertiary care centres. All were screened for LTB with tuberculin skin test (TST), QuantiFERON TB Gold® in tube (QFT) and T-SPOT.TB® (TSpot) on the same day. Cost-minimization and cost-effectiveness analysis, testing 8 screening test combinations, were conducted. Effectiveness was defined as the percentage of LTB treatment avoided and compared with TST alone. Cost were elicited in the payer perspective, included all the costs related to the screening procedure. RESULTS: No tuberculosis reactivation was observed after TNF-blocker initiation. TST followed by QFT if TST was positive was found as the best screening strategy, i.e. the less costly (-54€ compared to reference) and most effective (effectiveness 0.93), resulting in an incremental cost-effectiveness ratio of -192€ per treatment avoided. A probabilistic sensitivity analysis confirmed this result in 72.3% of simulations. CONCLUSION: TST followed by QFT if TST was positive is the most cost-effective strategy in screening for LTB in patients before starting anti-TNF therapy. TRIALREGNO: NCT00811343.

Effectiveness and cost-effectiveness of screening migrants for active tuberculosis and latent tuberculous infection.

With the advent of the World Health Organization End TB strategy, there has been renewed interest in screening for active tuberculosis (TB), and particularly latent tuberculous infection (LTBI). In low-incidence countries, a high proportion of TB cases are notified among migrants, which often occurs due to LTBI reactivation. We aimed to review the effectiveness and cost-effectiveness of screening migrants for active TB LTBI to inform and support the TB elimination strategy in low-incidence countries. We carried out a narrative review of English language articles published between 1 January 2000 and 31 June 2016 using the PubMed database. All studies that described the effectiveness or cost-effectiveness of active TB or LTBI screening among migrants were included. We identified 55 studies, and included 40 for the effectiveness of screening, 11 for cost-effectiveness and 4 that reported both. Screening for active TB can be effective and cost-effective depending on the setting, target group and screening approach. Pre-entry screening programmes have some impact on the epidemiology of the receiving countries. The effectiveness and cost-effectiveness of LTBI screening as predicted in mathematical models is also highly setting-specific, with best potential results achieved if screening is restricted to high-risk groups and/or to migrants from high-burden countries.

Methodological considerations for economic modelling of latent tuberculous infection screening in migrants.

Tuberculosis (TB) in migrants from endemic to low-incidence countries results mainly from the reactivation of latent tuberculous infection (LTBI). LTBI screening policies for migrants vary greatly between countries, and the evidence on the cost-effectiveness of the different approaches is weak and heterogeneous. The aim of this review was to assess the methodology used in published economic evaluations of LTBI screening among migrants to identify critical methodological options that must be considered when using modelling to determine value for money from different economic perspectives. Three electronic databases were searched and 10 articles were included. There was considerable variation across this small number of studies with regard to economic perspective, main outcomes, modelling technique, screening options and target populations considered, as well as in parameterisation of the epidemiological situation, test accuracy, efficacy, safety and programme performance. Only one study adopted a societal perspective; others adopted a health care or wider government perspective. Parameters representing the cascade of screening and treating LTBI varied widely, with some studies using highly aspirational scenarios. This review emphasises the need for a more harmonised approach for economic analysis, and better transparency in how policy options and economic perspectives influence methodological choices. Variability is justifiable for some parameters. However, sufficient data are available to standardise others. A societal perspective is ideal, but can be challenging due to limited data. Assumptions about programme performance should be based on empirical data or at least realistic assumptions. Results should be interpreted within specific contexts and policy options, with cautious generalisations.

Revisiting annual screening for latent tuberculosis infection in healthcare workers: a cost-effectiveness analysis.

BACKGROUND: In North America, tuberculosis incidence is now very low and risk to healthcare workers has fallen. Indeed, recent cohort data question routine annual tuberculosis screening in this context. We compared the cost-effectiveness of three potential strategies for ongoing screening of North American healthcare workers at risk of exposure. The analysis did not evaluate the cost-effectiveness of screening at hiring, and considered only workers with negative baseline tests. METHODS: A decision analysis model simulated a hypothetical cohort of 1000 workers following negative baseline tests, considering duties, tuberculosis exposure, testing and treatment. Two tests were modelled, the tuberculin skin test (TST) and QuantiFERON®-TB-Gold In-Tube (QFT). Three screening strategies were compared: (1) annual screening, where workers were tested yearly; (2) targeted screening, where workers with high-risk duties (e.g. respiratory therapy) were tested yearly and other workers only after recognised exposure; and (3) post exposure-only screening, where all workers were tested only after recognised exposure. Workers with high-risk duties had 1% annual risk of infection, while workers with standard patient care duties had 0.3%. In an alternate higher-risk scenario, the corresponding annual risks of infection were 3% and 1%, respectively. We projected costs, morbidity, quality-adjusted survival and mortality over 20 years after hiring. The analysis used the healthcare system perspective and a 3% annual discount rate. RESULTS: Over 20 years, annual screening with TST yielded an expected 2.68 active tuberculosis cases/1000 workers, versus 2.83 for targeted screening and 3.03 for post-exposure screening only. In all cases, annual screening was associated with poorer quality-adjusted survival, i.e. lost quality-adjusted life years, compared to targeted or post-exposure screening only. The annual TST screening strategy yielded an incremental cost estimate of $1,717,539 per additional case prevented versus targeted TST screening, which in turn cost an incremental $426,678 per additional case prevented versus post-exposure TST screening only. With the alternate "higher-risk" scenario, the annual TST strategy cost an estimated $426,678 per additional case prevented versus the targeted TST strategy, which cost an estimated $52,552 per additional case prevented versus post-exposure TST screening only. In all cases, QFT was more expensive than TST, with no or limited added benefit. Sensitivity analysis suggested that, even with limited exposure recognition, annual screening was poorly cost-effective. CONCLUSIONS: For most North American healthcare workers, annual tuberculosis screening appears poorly cost-effective. Reconsideration of screening practices is warranted.

A systematic review of economic models used to assess the cost-effectiveness of strategies for identifying latent tuberculosis in high-risk groups.

BACKGROUND: Timely diagnosis and treatment of latent tuberculosis infection (LTBI) through screening remains a key public health priority. Although globally it is recommended to screen people at high risk of developing TB, the economic evidence underpinning these recommendations is limited. This review critically appraised studies that had used a decision-analytical modelling framework to estimate the cost-effectiveness of interferon gamma release assays (IGRAs) compared to tuberculin skin test (TST) for detecting LTBI in high risk populations. METHODS: A comprehensive search of MEDLINE, EMBASE, NHS-EED was undertaken from 2009 up to June 2015. Studies were screened and extracted by independent reviewers. The study quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and the Philips' checklist, respectively. A narrative synthesis of the included studies was undertaken. RESULTS: Ten studies were included in this review. Two economic evaluations were conducted in a child population, six in an immunocompromised population and two in a recently arrived population from a country with a high incidence of TB. Most studies (n = 7) used a decision tree structure with Markov nodes. In general, all models were clearly described in terms of reporting quality, but were subject to limitations to structure and model inputs. Models have not elaborated on their setting or the perspective of the studies was not consistent with their analyses. Other concerns were related to derivation of prevalence, test accuracy and transition probabilities. CONCLUSION: Current methods available highlight limitations in the clinical effectiveness literature, model structures and assumptions, which impact on the robustness of the cost-effectiveness results. These models available are useful, but limited on the information that can be used to inform on future cost-effectiveness analysis. Until consideration is given on deriving the performance of tests used to identify LTBI that progresses to active TB, and the development of more comprehensive models, the economic benefit of LTBI testing with TST/IGRAs in high risk populations will remain unanswered.

A cost-benefit analysis of a proposed overseas refugee latent tuberculosis infection screening and treatment program.

BACKGROUND: This study explored the effect of screening and treatment of refugees for latent tuberculosis infection (LTBI) before entrance to the United States as a strategy for reducing active tuberculosis (TB). The purpose of this study was to estimate the costs and benefits of LTBI screening and treatment in United States bound refugees prior to arrival. METHODS: Costs were included for foreign and domestic LTBI screening and treatment and the domestic treatment of active TB. A decision tree with multiple Markov nodes was developed to determine the total costs and number of active TB cases that occurred in refugee populations that tested 55, 35, and 20 % tuberculin skin test positive under two models: no overseas LTBI screening and overseas LTBI screening and treatment. For this analysis, refugees that tested 55, 35, and 20 % tuberculin skin test positive were divided into high, moderate, and low LTBI prevalence categories to denote their prevalence of LTBI relative to other refugee populations. RESULTS: For a hypothetical 1-year cohort of 100,000 refugees arriving in the United States from regions with high, moderate, and low LTBI prevalence, implementation of overseas screening would be expected to prevent 440, 220, and 57 active TB cases in the United States during the first 20 years after arrival. The cost savings associated with treatment of these averted cases would offset the cost of LTBI screening and treatment for refugees from countries with high (net cost-saving: $4.9 million) and moderate (net cost-saving: $1.6 million) LTBI prevalence. For low LTBI prevalence populations, LTBI screening and treatment exceed expected future TB treatment cost savings (net cost of $780,000). CONCLUSIONS: Implementing LTBI screening and treatment for United States bound refugees from countries with high or moderate LTBI prevalence would potentially save millions of dollars and contribute to United States TB elimination goals. These estimates are conservative since secondary transmission from tuberculosis cases in the United States was not considered in the model.

A Systematic Review of Studies Evaluating the Cost Utility of Screening High-Risk Populations for Latent Tuberculosis Infection.

BACKGROUND: As tuberculosis screening trends to targeting high-risk populations, knowing the cost effectiveness of such screening is vital to decision makers. OBJECTIVES: The purpose of this review was to compile cost-utility analyses evaluating latent tuberculosis infection (LTBI) screening in high-risk populations that used quality-adjusted life-years (QALYs) as their measure of effectiveness. DATA SOURCES: A literature search of MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Web of Knowledge, and PubMed was performed from database start to November 2014. INCLUSION CRITERIA: Studies performed in populations at high risk of LTBI and subsequent reactivation that used the QALY as an effectiveness measure were included. STUDY APPRAISAL AND SYNTHESIS: Quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. Data extracted included tuberculin skin test (TST) and/or interferon-gamma release assay (IGRA) use, economic, screening, treatment, health state, and epidemiologic parameters. Data were summarized in regard to consistency in model parameters and the incremental cost-effectiveness ratio (ICER), with costs adjusted to 2013 US dollars. RESULTS: Of 415 studies identified, ultimately eight studies were included in the review. Most took a societal perspective (n = 4), used lifetime time horizons (n = 6), and used Markov models (n = 8). Screening of adult immigrants was found to be cost effective with a TST in one study, but moderately cost effective with an IGRA in another study; screening immigrants arriving more than 5 years prior with an IGRA was moderately cost effective until 44 years of age (n = 1). Screening HIV-positive patients was highly cost effective with a TST (n = 1) and moderately cost effective with an IGRA (n = 1). Screening in those with renal diseases (n = 2) and diabetes (n = 1) was not cost effective. LIMITATIONS: Very few studies used the QALY as their effectiveness measure. Parameter and study design inconsistencies limit the comparability of studies. CONCLUSIONS: With validity issues in terms of parameters and assumptions, any conclusion should be interpreted with caution. Despite this, some cautionary recommendations emerged: screening HIV patients with a TST is highly cost effective, while screening adult immigrants with an IGRA is moderately cost effective.

Decreasing cost effectiveness of testing for latent TB in HIV in a low TB incidence area.

Testing for latent tuberculosis infection (LTBI) in HIV-infected persons in low tuberculosis (TB) incidence areas is often recommended. Using contemporary, clinical data, we report the yield and cost-effectiveness of testing all HIV attendees, two current UK strategies and no LTBI testing. Economic modelling was performed utilising 10-year follow up data from a large HIV clinical cohort. Outcomes were numbers of cases of active TB and incremental cost per quality-adjusted life year (QALY) gained. Between 2000 and 2010, 256 people were treated for TB/HIV co-infection. 72 (28%) occurred ≥3 months after HIV diagnosis and may have been prevented by LTBI testing. Between 2000 and 2005, the incremental cost per QALY gained for the British HIV Association (BHIVA) and UK National Institute of Care Excellence (NICE) strategies, and testing all clinic attendees was €6270, €6998 and €33,473, respectively. These rose to €9332, €32,564 and €74,067, respectively, between 2005 and 2010. Probabilistic sensitivity analysis suggested that at a threshold of €24,000 per additional QALY, the most cost-effective strategies would be NICE or testing all in 2000-2005 and BHIVA during 2005-2010. Both UK testing regimens missed cases but are cost-effective compared with no testing. Using recent data, they all became more expensive, suggesting that alternative or more targeted TB testing strategies must be considered.