Dataset Information

Active screening for tuberculosis in high-incidence Inuit communities in Canada: a cost-effectiveness analysis

ABSTRACT:

Background:

Active screening for tuberculosis (TB) involves systematic detection of previously undiagnosed TB disease or latent TB infection (LTBI). It may be an important step toward elimination of TB among Inuit in Canada. We aimed to evaluate the cost-effectiveness of community-wide active screening for TB infection and disease in 2 Inuit communities in Nunavik.

Methods:

We incorporated screening data from the 2 communities into a decision analysis model. We predicted TB-related health outcomes over a 20-year time frame, beginning in 2019. We assessed the cost-effectiveness of active screening in the presence of varying outbreak frequency and intensity. We also considered scenarios involving variation in timing, impact and uptake of screening programs.

Results:

Given a single large outbreak in 2019, we estimated that 1 round of active screening reduced TB disease by 13% (95% uncertainty range −3% to 27%) and was cost saving compared with no screening, over 20 years. In the presence of simulated large outbreaks every 3 years thereafter, a single round of active screening was cost saving, as was biennial active screening. Compared with a single round, we also determined that biennial active screening reduced TB disease by 59% (95% uncertainty range 52% to 63%) and was estimated to cost Can$6430 (95% uncertainty range −$29 131 to $13 658 in 2019 Can$) per additional active TB case prevented. With smaller outbreaks or improved rates of treatment initiation and completion for people with LTBI, we determined that biennial active screening remained reasonably cost-effective compared with no active screening.

Interpretation:

Active screening is a potentially cost-saving approach to reducing disease burden in Inuit communities that have frequent TB outbreaks.

SUBMITTER: Uppal A

PROVIDER: S-EPMC8565977 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundTuberculosis (TB) is an important public health problem in Inuit communities across Canada, with an annual incidence rate in 2017 that was nearly 300 times higher than in Canadian-born non-Indigenous individuals. Social and behavioral factors that are prevalent in the North, such as commercial tobacco use, excessive alcohol use, food insecurity and overcrowded housing put individuals at higher risk for TB morbidity and mortality. We examined the potential impact of mitigation strategies for these risk factors, in reducing TB burden in this setting.MethodsWe created a transmission model to simulate the epidemiology of TB in Nunavut, Canada. We then used a decision analysis model to assess the potential impact of several evidence-based strategies targeting tobacco use, excessive alcohol use, food insecurity and overcrowded housing. We predicted TB incidence, TB-related deaths, quality adjusted life years (QALYs), and associated costs and cost-effectiveness over 20 years. All costs were expressed in 2018 Canadian dollars.ResultsCompared to a status quo scenario with no new interventions for these risk factors, the reduction strategy for tobacco use was most effective and cost-effective, reducing TB incidence by 5.5% (95% uncertainty range: 2.7-11%) over 20 years, with an estimated cost of $95,835 per TB case prevented and $49,671 per QALY gained. The addition of the food insecurity reduction strategy reduced incidence by a further 2% (0.5-3%) compared to the tobacco cessation strategy alone, but at significant cost.ConclusionsStrategies that aim to reduce commercial tobacco use and improve food security will likely lead to modest reductions in TB morbidity and mortality. Although important for the communities, strategies that address excess alcohol use and overcrowding will likely have a more limited impact on TB-related outcomes at current scale, and are associated with much higher cost. Their benefits will be more substantial with scale up, which will also likely have important downstream impacts such as improved mental health, educational attainment and food security.

Project description:BackgroundSystematic screening for active tuberculosis (TB) is a strategy which requires the health system to seek out individuals, rather than waiting for individuals to self-present with symptoms (i.e., passive case finding). Our review aimed to summarize the current economic evidence and understand the costs and cost-effectiveness of systematic screening approaches among high-risk groups and settings.MethodsWe conducted a systematic review on economic evaluations of screening for TB disease targeting persons with clinical and/or structural risk factors, such as persons living with HIV (PLHIV) or persons experiencing homelessness. We searched three databases for studies published between January 1, 2010 and February 1, 2020. Studies were included if they reported cost and a key outcome measure. Owing to considerable heterogeneity in settings and type of screening strategy, we synthesized data descriptively.ResultsA total of 27 articles were included in our review; 19/27 (70%) took place in high TB burden countries. Seventeen studies took place among persons with clinical risk factors, including 14 among PLHIV, while 13 studies were among persons with structural risk factors. Nine studies reported incremental cost-effectiveness ratios (ICERs) ranging from US$51 to $1980 per disability-adjusted life year (DALY) averted. Screening was most cost-effective among PLHIV. Among persons with clinical and structural risk factors there was limited evidence, but screening was generally not shown to be cost-effective.ConclusionsStudies showed that screening is most likely to be cost-effective in a high TB prevalence population. Our review highlights that to reach the "missing millions" TB programmes should focus on simple, cheaper initial screening tools (i.e., symptom screen and CXR) followed by molecular diagnostic tools (i.e., Xpert®) among the highest risk groups in the local setting (i.e., PLHIV, urban slums). Programmatic costs greatly impact cost-effectiveness thus future research should provide both fixed and variable costs of screening interventions to improve comparability.

Project description: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.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.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.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.

Project description:Screening asylum-seekers for active pulmonary tuberculosis is common practice among many European countries with low incidence of tuberculosis. The reported yields vary substantially, partly due to the heterogeneous and dynamic nature of asylum-seeking populations. Rather than screening all new arrivals (indiscriminate screening), a few countries apply targeted screening based on incidence of tuberculosis in asylum-seekers' country of origin. However, evaluations of its cost-effectiveness have been scarce. The aim of this modelling study was to assess whether the introduction of a screening threshold based on the tuberculosis incidence in the country of origin is sensible from an economic perspective. To this end, we compare the current, indiscriminate screening policy for pulmonary tuberculosis in Germany with a hypothetical targeted screening programme using several potential screening thresholds based on WHO-reported incidence of tuberculosis in countries of origin. Screening data is taken from a large German federal state over 14 years (2002-2015). Incremental cost-effectiveness is measured as cost per case found and cost per case prevented. Our analysis shows that incremental cost-effectiveness ratios (ICERs) of screening asylum-seekers from countries with an incidence of 50 to 250/100,000 range between 15,000€ and 17,000€ per additional case found when compared to lower thresholds. The ICER for screening asylum-seekers from countries with an incidence <50/100,000 is 112,000€ per additional case found. Costs per case prevented show a similar increase in costs. The high cost per case found and per case prevented at the <50/100,000 threshold scenario suggests this threshold to be a sensible cut-off for targeted screening. Acknowledging that no screening measure can find all cases of tuberculosis, and that reactivation of latent infections makes up a large proportion of foreign-born cases, targeting asylum-seekers from countries with an incidence above 50/100,000 is likely to be a more reasonable screening measure for the prevention and control of tuberculosis than indiscriminate screening measures.