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

A cost-effectiveness evaluation of latent tuberculosis infection screening of a migrant population in Malaysia

To estimate the costs and benefits of screening for latent tuberculosis infection (LTBI) in a migrant population in Malaysia. An economic model was developed from a Malaysian healthcare perspective to compare QuantiFERON-TB Gold Plus (QuantiFERON) with the tuberculin skin test (TST). A decision tree was used to capture outcomes relating to LTBI screening followed by a Markov model that simulated the lifetime costs and benefits of the patient cohort. The Markov model did not capture the impact of secondary infections. The model included an R shiny interactive interface to allow adaptation to other scenarios and settings. QuantiFERON is both more effective and less costly than TST (dominant). Compared with QuantiFERON, the lifetime risk of developing active TB increases by approximately 40% for TST due to missed LTBI cases during screening (i.e. a higher number of false negative cases for TST). For a migrant population in Malaysia, QuantiFERON is cost-effective when compared with TST. Further research should consider targeted LTBI screening for migrants in Malaysia based on common risk factors.

A systematic review of cost-utility analyses of screening methods in latent tuberculosis infection in high-risk populations

Background

The World Health Organisation (WHO) recommends that testing and treatment for latent tuberculosis infection (LTBI) should be undertaken in high-risk groups using either interferon gamma release assays (IGRAs) or a tuberculin skin test (TST). As IGRAs are more expensive than TST, an assessment of the cost-effectiveness of IGRAs can guide decision makers on the most appropriate choice of test for different high-risk populations. This current review aimed to provide the most up to date evidence on the cost-effectiveness evidence on LTBI testing in high-risk groups—specifically evidence reporting the costs per QALY of different testing strategies.

Methods

A comprehensive search of databases including MEDLINE, EMBASE and NHS-EED was undertaken from 2011 up to March 2021. Studies were screened and extracted by two independent reviewers. The study quality was assessed using the Bias in Economic Evaluation Checklist (ECOBIAS). A narrative synthesis of the included studies was undertaken.

Results

Thirty-two studies reported in thirty-three documents were included in this review. Quality of included studies was generally high, although there was a weakness across all studies referencing sources correctly and/or justifying choices of parameter values chosen or assumptions where parameter values were not available. Inclusions of IGRAs in testing strategies was consistently found across studies to be cost-effective but this result was sensitive to underlying LTBI prevalence rates.

Conclusion

While some concerns remain about uncertainty in parameter values used across included studies, the evidence base since 2010 has grown with modelling approaches addressing the weakness pointed out in previous reviews but still reaching the same conclusion that IGRAs are likely to be cost-effective in high-income countries for high-risk populations. Evidence is also required on the cost-effectiveness of different strategies in low to middle income countries and countries with high TB burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02149-x.

A Systematic Review of Economic Evaluations of Active Tuberculosis Treatments

Background: The disease burden of active tuberculosis (TB) is considerable, but systematic reviews of economic evaluations of active TB treatments are scarce. Methods: PubMed, EMBASE, and the Cochrane Library databases were used to search for articles on cost-effectiveness analysis or cost-utility analysis that economically evaluated active TB treatments, which were then systematically reviewed by two independent reviewers. We extracted vital components of the included studies, such as country, population, intervention/comparator, primary outcome, values of outcomes, thresholds, model type, time horizon, and health states included in the model. Results: Seventeen studies were included in this systematic review. Thirteen dealt with interventions of medications, and the remaining four compared care strategies. The Markov model was the most commonly used tool to compare medications, whereas studies on care plans mainly used decision trees. The most commonly used primary outcome was disability-adjusted life years, followed by quality-adjusted life years. For treatment-naïve TB, the 4-month regimen was more cost-effective than the 6-month regimen mainly in low- and middle-income countries. For multidrug-resistant TB, a bedaquiline-based regimen was cost-effective. For multidrug-resistant TB, decentralized care that employed the use of home or mobile devices was more cost-effective than hospital-based centralized care in low- and middle-income countries. Conclusion: New treatment strategies to improve therapeutic outcomes by enhancing treatment adherence, such as regimens with shorter durations (2 or 4 months) and decentralized care, or new anti-TB agents (e.g., bedaquiline) have been suggested as cost-effective interventions for active TB. This review provides information on the economic evaluation of active TB from good-quality studies, thus aiding the future economic evaluation of active TB.

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.

Active case finding of pulmonary TB in a European refugee camp: lessons learnt from Oinofyta hosting site in Greece

OBJECTIVES

To report on an active case finding (ACF) intervention that took place in the migrant camp of Oinofyta, Greece, upon suspicion of active TB transmission.

METHODS

Upon diagnosis of 3 TB cases among camp residents, an ACF intervention among contacts was implemented. All camp residents were offered two-step screening, that is tuberculin skin testing (TST) followed by chest X-ray in case of positive TST (defined as ≥5 mm).

RESULTS

336 of 379 (89%) camp residents underwent TST testing, of whom 110 (33%) exhibited a positive skin reaction. The rate of positive TST results was particularly high in the elderly and significantly higher in adults than in children. Differences by sex or nationality were not observed. Of the 110 cases with positive TST, only 75 underwent chest X-ray, resulting in the detection of one pulmonary TB case in an adult woman.

CONCLUSIONS

In the given intervention context, two-step ACF proved to be operationally cumbersome, with many residents lost to follow-up and a high Number Needed to Screen. Simpler ACF designs should be pilot-tested in similar settings in the future, and blanket screening of all camp residents should be reconsidered. Conclusions drawn by these exercises should pave the way for adopting a comprehensive, context-specific and evidence-based national strategy on TB in migrants.

How effective are approaches to migrant screening for infectious diseases in Europe? A systematic review

Rates of migration to Europe, and within Europe, have increased in recent years, with considerable implications for health systems. Migrants in Europe face a disproportionate burden of tuberculosis, HIV, and hepatitis B and C, yet experience a large number of barriers to accessing statutory health care on arrival. A better understanding of how to deliver effective and cost-effective screening, vaccination, and health services to this group is now crucial. We did a systematic review to document and assess the effectiveness and cost-effectiveness of approaches used for infectious diseases screening, and to explore facilitators and barriers experienced by migrants to accessing screening programmes. Following PRISMA guidelines, we searched Embase, PubMed, PsychINFO, the Cochrane Library, and Web of Science (1989 to July 1, 2015, updated on Jan 1, 2018), with no language restrictions, and systematically approached experts across the European Union (EU) for grey literature. Inclusion criteria were primary research studies assessing screening interventions for any infectious disease in the migrant (foreign-born) population residing in EU or European Economic Area (EEA) countries. Primary outcomes were the following effectiveness indicators: uptake of screening, coverage, infections detected, and treatment outcomes. Of 4112 unique records, 47 studies met our inclusion criteria, from ten European countries (Belgium, Denmark, France, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the UK) encompassing 248 402 migrants. We found that most European countries screening migrants focus on single diseases only-predominantly active or latent tuberculosis infection-and specifically target asylum seekers and refugees, with 22 studies reporting on other infections (including HIV and hepatitis B and C). An infection was detected in 3·74% (range 0·00-95·16) of migrants. Latent tuberculosis had the highest prevalence across all infections (median 15·02% [0·35-31·81]). Uptake of screening by migrants was high (median 79·50% [18·62-100·00]), particularly in primary health-care settings (uptake 96·77% [76·00-100·00]). However, in 24·62% (0·12-78·99) of migrants screening was not completed and a final diagnosis was not made. Pooled data highlight high treatment completion in migrants (83·79%, range 0·00-100·00), yet data were highly heterogeneous for this outcome, masking important disparities between studies and infections, with only 54·45% (35·71-72·27) of migrants with latent tuberculosis ultimately completing treatment after screening. Coverage of the migrant population in Europe is low (39·29% [14·53-92·50]). Data on cost-effectiveness were scarce, but suggest moderate to high cost-effectiveness of migrant screening programmes depending on migrant group and disease targeted. European countries have adopted a variety of approaches to screening migrants for infections; however, these are limited in scope to single diseases and a narrow subset of migrants, with low coverage. More emphasis must be placed on developing innovative and sustainable strategies to facilitate screening and treatment completion and improve health outcomes, encompassing multiple key infections with consideration given to a wider group of high-risk migrants. Policy makers and researchers involved with global migration need to ensure a longer-term view on improving health outcomes in migrant populations as they integrate into health systems in host countries.

Disparities in model-based cost-effectiveness analyses of tuberculosis diagnosis: A systematic review

Background

Structural approach disparities were minimally addressed in past systematic reviews of model-based cost-effectiveness analyses addressing Tuberculosis management strategies. This review aimed to identify the structural approach disparities in model-based cost-effectiveness analysis studies addressing Tuberculosis diagnosis and describe potential hazards caused by those disparities.

Methods

A systematic search to identify studies published before October 2015 was performed in five electronic databases. After removal of duplication, studies’ titles and abstracts were screened based on predetermined criteria. The full texts of potentially relevant studies were subsequently screened and excluded when they did not address active pulmonary Tuberculosis diagnosis. Quality of the studies was assessed using the “Philips’ checklist.” Various data regarding general information, cost-effectiveness results, and disease modeling were extracted using standardized data extraction forms. Data pertaining to models’ structural approaches were compared and analyzed qualitatively for their applicability in various study settings, as well as their potential influence on main outcomes and cost-effectiveness conclusion.

Results

A total of 27 studies were included in the review. Most studies utilized a static model, which could underestimate the cost-effectiveness of the diagnostic tools strategies, due to the omission of indirect diagnosis effects, i.e. transmission reduction. A few structural assumption disparities were found in the dynamic models. Extensive disparities were found in the static models, consisting of varying structural assumptions regarding treatment outcomes, clinical diagnosis and empirical treatment, inpatient discharge decision, and re-diagnosis of false negative patients.

Conclusion

In cost-effectiveness analysis studies addressing active pulmonary Tuberculosis diagnosis, models showed numerous disparities in their structural approaches. Several structural approaches could be inapplicable in certain settings. Furthermore, they could contribute to under- or overestimation of the cost-effectiveness of the diagnosis tools or strategies. They could thus lead to ambiguities and difficulties when interpreting a study result. A set of recommendations is proposed to manage issues related to these structural disparities.

Screening for latent and active tuberculosis infection in the elderly at admission to residential care homes: A cost-effectiveness analysis in an intermediate disease burden area

BACKGROUND

Tuberculosis (TB) in the elderly remains a challenge in intermediate disease burden areas like Hong Kong. Given a higher TB burden in the elderly and limited impact of current case-finding strategy by patient-initiated pathway, proactive screening approaches for the high-risk group could be optimal and increasingly need targeted economic evaluations. In this study, we examined whether and under what circumstance the screening strategies are cost-effective compared with no screening strategy for the elderly at admission to residential care homes.

METHODS

A decision analytic process based on Markov model was adopted to evaluate the cost-effectiveness of four strategies: (i) no screening, (ii) TB screening (CXR) and (iii) TB screening (Xpert) represent screening for TB in symptomatic elderly by chest X-ray and Xpert® MTB/RIF respectively, and (iv) LTBI/TB screening represents screening for latent and active TB infection by QuantiFERON®-TB Gold In-Tube and chest X-ray. The target population was a hypothetical cohort of 65-year-old people, using a health service provider perspective and a time horizon of 20 years. The outcomes were direct medical costs, life-years and quality-adjusted life-years (QALYs) measured by incremental cost-effectiveness ratio (ICER).

RESULTS

In the base-case analysis, no screening was the most cost-saving; TB screening (CXR) was dominated by TB screening (Xpert); LTBI/TB screening resulted in more life-years and QALYs accrued. The ICERs of LTBI/TB screening were US$19,712 and US$29,951 per QALY gained compared with no screening and TB screening (Xpert), respectively. At the willingness-to-pay threshold of US$50,000 per QALY gained, LTBI/TB screening was the most cost-effective when the probability of annual LTBI reactivation was greater than 0.155% and acceptability of LTBI/TB screening was greater than 38%. In 1,000 iterations of Monte Carlo simulation, the probabilities of no screening, TB screening (CXR), TB screening (Xpert), and LTBI/TB screening to be cost-effective were 0, 1.3%, 20.1%, and 78.6% respectively.

CONCLUSIONS

Screening for latent and active TB infection in Hong Kong elderly people at admission to residential care homes appears to be highly effective and cost-effective. The key findings may be the next key factor to bring down TB endemic in the elderly population among intermediate TB burden areas.

Cost-effectiveness of post-landing latent tuberculosis infection control strategies in new migrants to Canada

BACKGROUND

The majority of tuberculosis in migrants to Canada occurs due to reactivation of latent TB infection. Risk of tuberculosis in those with latent tuberculosis infection can be significantly reduced with treatment. Presently, only 2.4% of new migrants are flagged for post-landing surveillance, which may include latent tuberculosis infection screening; no other migrants receive routine latent tuberculosis infection screening. To aid in reducing the tuberculosis burden in new migrants to Canada, we determined the cost-effectiveness of using different latent tuberculosis infection interventions in migrants under post-arrival surveillance and in all new migrants.

METHODS

A discrete event simulation model was developed that focused on a Canadian permanent resident cohort after arrival in Canada, utilizing a ten-year time horizon, healthcare system perspective, and 1.5% discount rate. Latent tuberculosis infection interventions were evaluated in the population under surveillance (N = 6100) and the total cohort (N = 260,600). In all evaluations, six different screening and treatment combinations were compared to the base case of tuberculin skin test screening followed by isoniazid treatment only in the population under surveillance. Quality adjusted life years, incident tuberculosis cases, and costs were recorded for each intervention and incremental cost-effectiveness ratios were calculated in relation to the base case.

RESULTS

In the population under surveillance (N = 6100), using an interferon-gamma release assay followed by rifampin was dominant compared to the base case, preventing 4.90 cases of tuberculosis, a 4.9% reduction, adding 4.0 quality adjusted life years, and saving $353,013 over the ensuing ten-years. Latent tuberculosis infection screening in the total population (N = 260,600) was not cost-effective when compared to the base case, however could potentially prevent 21.8% of incident tuberculosis cases.

CONCLUSIONS

Screening new migrants under surveillance with an interferon-gamma release assay and treating with rifampin is cost saving, but will not significantly impact TB incidence. Universal latent tuberculosis infection screening and treatment is cost-prohibitive. Research into using risk factors to target screening post-landing may provide alternate solutions.

Quality of pharmacoeconomic research in China: A systematic review

BACKGROUND

The number of pharmacoeconomic publications in the literature from China has risen rapidly, but the quality of pharmacoeconomic publications from China has not been analyzed.

OBJECTIVES

This study aims to identify all recent pharmacoeconomic publications from China, to critically appraise the reporting quality, and to summarize the results.

METHODS

Four databases (PubMed, Web of Science, Medline, and EmBase) were searched for original articles published up to December 31, 2014. The Consolidated Health Economic Evaluation Reporting Standards statement including 24 items was used to assess the quality of reporting of these articles.

RESULTS

Of 1046 articles identified, 32 studies fulfilled the inclusion criteria. They were published in 23 different journals. Quality of reporting varied between studies, with an average score of 18.7 (SD = 4.33) out of 24 (range 9-23.5). There was an increasing trend of pharmacoeconomic publications and reporting quality over years from 2003 to 2014. According to the Consolidated Health Economic Evaluation Reporting Standards, the reporting quality for the items including "title," "comparators of method," and "measurement of effectiveness" are quite low, with less than 50% of studies fully satisfying these reporting standards. In contrast, reporting was good for the items including "introduction," "study perspective," "choice of health outcomes," "study parameters," "characterizing heterogeneity," and "discussion," with more than 75% of the articles satisfying these reporting criteria. The remaining items fell in between these 2 extremes, with 50% to 75% of studies satisfying these criteria.

CONCLUSION

Our study suggests the need for improvement in a number of reporting criteria. But the criteria for which reporting quality was low seem to be limitations that would be straightforward to correct in future studies.