Cost-effectiveness of Low-complexity Screening Tests in Community-based Case-finding for Tuberculosis.

INTRODUCTION: In high-burden settings, low-complexity screening tests for tuberculosis (TB) could expand the reach of community-based case-finding efforts. The potential costs and cost-effectiveness of approaches incorporating these tests are poorly understood. METHODS: We developed a microsimulation model assessing 3 approaches to community-based case-finding in hypothetical populations (India-, South Africa-, The Philippines-, Uganda-, and Vietnam-like settings) with TB prevalence 4 times that of national estimates: (1) screening with a point-of-care C-reactive protein (CRP) test, (2) screening with a more sensitive "Hypothetical Screening test" (95% sensitive for Xpert Ultra-positive TB, 70% specificity; equipment/labor costs similar to Xpert Ultra, but using a $2 cartridge) followed by sputum Xpert Ultra if positive, or (3) testing all individuals with sputum Xpert Ultra. Costs are expressed in 2023 US dollars and include treatment costs. RESULTS: Universal Xpert Ultra was estimated to cost a mean $4.0 million (95% uncertainty range: $3.5 to $4.6 million) and avert 3200 (2600 to 3900) TB-related disability-adjusted life years (DALYs) per 100 000 people screened ($670 [The Philippines] to $2000 [Vietnam] per DALY averted). CRP was projected to cost $550 (The Philippines) to $1500 (Vietnam) per DALY averted but with 44% fewer DALYs averted. The Hypothetical Screening test showed minimal benefit compared to universal Xpert Ultra, but if specificity were improved to 95% and per-test cost to $4.5 (all-inclusive), this strategy could cost $390 (The Philippines) to $940 (Vietnam) per DALY averted. CONCLUSIONS: Screening tests can meaningfully improve the cost-effectiveness of community-based case-finding for TB but only if they are sensitive, specific, and inexpensive.

mHealth to improve implementation of TB contact investigation: a case study from Uganda.

BACKGROUND: Implementation science offers a systematic approach to adapting innovations and delivery strategies to new contexts but has yet to be widely applied in low- and middle-income countries. The Fogarty Center for Global Health Studies is sponsoring a special series, "Global Implementation Science Case Studies," to address this gap. METHODS: We developed a case study for this series describing our approach and lessons learned while conducting a prospective, multi-modal study to design, implement, and evaluate an implementation strategy for TB contact investigation in Kampala, Uganda. The study included formative, evaluative, and summative phases that allowed us to develop and test an adapted contact investigation intervention involving home-based sample collection for TB and HIV testing. We concurrently developed a multi-component mHealth implementation strategy involving fingerprint scanning, electronic decision support, and automated reporting of test results via text message. We then conducted a household-randomized, hybrid implementation-effectiveness trial comparing the adapted intervention and implementation strategy to usual care. Our assessment included nested quantitative and qualitative studies to understand the strategy's acceptability, appropriateness, feasibility, fidelity, and costs. Reflecting on this process with a multi-disciplinary team of implementing researchers and local public health partners, we provide commentary on the previously published studies and how the results influenced the adaptation of international TB contact investigation guidelines to fit the local context. RESULTS: While the trial did not show improvements in contact investigation delivery or public health outcomes, our multi-modal evaluation strategy helped us identify which elements of home-based, mHealth-facilitated contact investigation were feasible, acceptable, and appropriate and which elements reduced its fidelity and sustainability, including high costs. We identified a need for better tools for measuring implementation that are simple, quantitative, and repeatable and for greater attention to ethical issues in implementation science. CONCLUSIONS: Overall, a theory-informed, community-engaged approach to implementation offered many learnings and actionable insights for delivering TB contact investigation and using implementation science in low-income countries. Future implementation trials, especially those incorporating mHealth strategies, should apply the learnings from this case study to enhance the rigor, equity, and impact of implementation research in global health settings.

Multicomponent strategy with decentralised molecular testing for tuberculosis in Uganda: a cost and cost-effectiveness analysis.

BACKGROUND: Decentralised molecular testing for tuberculosis could reduce missed diagnoses and losses to follow-up in high-burden settings. The aim of this study was to evaluate the cost and cost-effectiveness of the Xpert Performance Evaluation for Linkage to Tuberculosis Care (XPEL-TB) study strategy, a multicomponent strategy including decentralised molecular testing for tuberculosis, in Uganda. METHODS: We conducted a costing and cost-effectiveness analysis nested in a pragmatic cluster-randomised trial of onsite (decentralised) versus hub-and-spoke (centralised) testing for tuberculosis with Xpert MTB/RIF Ultra (Xpert) in 20 community health centres in Uganda. We collected empirical data on the cost of the XPEL-TB strategy (decentralised Xpert testing, workflow redesign, and performance feedback) and routine tuberculosis testing (onsite smear microscopy with specimen transport for centralised Xpert testing) from the health system perspective. Time-and-motion studies were performed to estimate activity-based service costs. Cost-effectiveness was assessed as the incremental cost (2019 US$) per tuberculosis diagnosis and per 14-day treatment initiation. FINDINGS: The XPEL-TB study ran from Oct 22, 2018, to March 1, 2020. Effectiveness and cost-effectiveness outcomes were assessed from Dec 1, 2018, to Nov 30, 2019 and included 4867 women and 3139 men. On a per-test basis, the cost of decentralised ($20·46, range $17·85-25·72) and centralised ($18·20, range $16·58-24·25) Xpert testing was similar. However, decentralised testing resulted in more patients receiving appropriate Xpert testing, so the per-patient cost of decentralised testing was higher: $20·28 (range $17·68-25·48) versus $9·59 (range $7·62-14·34). The XPEL-TB strategy was estimated to cost $1332 (95% uncertainty range $763-5558) per incremental tuberculosis diagnosis and $687 ($501-1207) per incremental patient initiating tuberculosis treatment within 14 days. Cost-effectiveness was reduced in sites performing fewer than 150-250 tests annually. INTERPRETATION: The XPEL-TB strategy facilitated higher rates of Xpert testing for tuberculosis at a similar per-test cost and modest incremental cost per tuberculosis diagnosis and treatment initiation. Decentralised Xpert testing, with appropriate implementation supports, should be scaled up to clinics with sufficient testing volume to support a single-module device. FUNDING: The National Heart, Lung, and Blood Institute.

Cost and Cost-Effectiveness of a Digital Adherence Technology for Tuberculosis Treatment Support in Uganda.

OBJECTIVES: Digital adherence technologies like 99DOTS are increasingly considered as an alternative to directly observed therapy for tuberculosis (TB) treatment supervision. We evaluated the cost and cost-effectiveness of 99DOTS in a high-TB-burden setting. METHODS: We assessed the costs of implementing 99DOTS in Uganda through a pragmatic, stepped-wedge randomized trial. We measured costs from the health system perspective at 5 of 18 study facilities. Self-reported service activity time data were used to assess activity-based service costs; other costs were captured from budgets and key informant discussions using standardized forms. We estimated costs and effectiveness considering the 8-month study period ("trial specific") and using a 5-year time horizon ("extended activities"), the latter including a "marginal clinic" expansion scenario that ignored above-site implementation costs. Cost-effectiveness was assessed as cost per patient successfully completing treatment, using Monte Carlo simulation, cost-effectiveness acceptability curves, and sensitivity analyses to evaluate uncertainty and robustness of results. RESULTS: The total cost of implementing 99DOTS in the "trial-specific" scenario was $99 554 across 18 clinics (range $3771-$6238 per clinic). The cost per treatment success in the "trial-specific" scenario was $355 (range $229-$394), falling to $59 (range $50-$70) assuming "extended activities," and $49 (range $42-$57) in the "marginal clinic" scenario. The incremental cost-effectiveness of 99DOTS in the "extended-activity" scenario was $355 per incremental treatment success. CONCLUSIONS: Costs and cost-effectiveness of 99DOTS were influenced by the degree to which infrastructure is scaled over time. If sustained and scaled up, 99DOTS can be a cost-effective option for TB treatment adherence support in high-TB-burden settings like Uganda.

Addressing health disparities through implementation science-a need to integrate an equity lens from the outset.

There is increasing attention being given to opportunities and approaches to advance health equity using implementation science. To reduce disparities in health, it is crucial that an equity lens is integrated from the earliest stages of the implementation process. In this paper, we outline four key pre-implementation steps and associated questions for implementation researchers to consider that may help guide selection and design of interventions and associated implementation strategies that are most likely to reach and be effective in reducing health disparities among vulnerable persons and communities.

Where will it end? Pathways to care and catastrophic costs following negative TB evaluation in Uganda.

INTRODUCTION: Catastrophic costs incurred by tuberculosis (TB) patients have received considerable attention, however little is known about costs and pathways to care after a negative TB evaluation. MATERIALS AND METHODS: We conducted a cross-sectional study of 70 patients with a negative TB evaluation at four community health centres in rural and peri-urban Uganda. Patients were traced 9 months post-evaluation using contact information from TB registers. We collected information on healthcare visits and implemented locally-validated costing questionnaires to assess the financial impact of their symptoms post-evaluation. RESULTS: Of 70 participants, 57 (81%) were traced and 53 completed the survey. 31/53 (58%) surveyed participants returned to healthcare facilities post-evaluation, making a median of 2 visits each (interquartile range [IQR] 1-3). 11.3% (95%CI 4.3-23.0%) of surveyed patients and 16.1% (95%CI 5.5-33.7%) of those returning to healthcare facilities incurred catastrophic costs (i.e., spent >20% annual household income). Indirect costs related to lost work represented 80% (IQR 32-100%) of total participant costs. CONCLUSIONS: Patients with TB symptoms who experience financial catastrophe after negative TB evaluation may represent a larger absolute number of patients than those suffering from costs due to TB. They may not be captured by existing definitions of non-TB catastrophic health expenditure.

Implementing pediatric inpatient asthma pathways.

OBJECTIVE: Pathways are succinct, operational versions of evidence-based guidelines. Studies have demonstrated pathways improve quality of care for children hospitalized with asthma, but we have limited information on other key factors to guide hospital leaders and clinicians in pathway implementation efforts. Our objective was to evaluate the adoption, implementation, and reach of inpatient pediatric asthma pathways. METHODS: This was a mixed-methods study of hospitals participating in a national collaborative to implement pathways. Data sources included electronic surveys of implementation leaders and staff, field observations, and chart review of children ages 2-17 years admitted with a primary diagnosis of asthma. Outcomes included adoption by hospitals, pathway implementation factors, and reach of pathways to children hospitalized with asthma. Quantitative data were analyzed using descriptive statistics and multivariable regression. Qualitative data were analyzed using thematic content analysis. RESULTS: Eighty-five hospitals enrolled; 68 (80%) adopted/completed the collaborative. These 68 hospitals implemented pathways with overall high fidelity, implementing a median of 5 of 5 core pathway components (Interquartile Range [IQR] 4-5) in a median of 5 months (IQR 3-9). Implementation teams reported a median time cost of 78 h (IQR: 40-120) for implementation. Implementation leaders reported the values of pathway implementation included improvements in care, enhanced interdisciplinary collaboration, and access to educational resources. Leaders reported barriers in modifying electronic health records (EHRs), and only 63% of children had electronic pathway orders placed. CONCLUSIONS: Hospitals implemented pathways with high fidelity. Barriers in modifying EHRs may have limited the reach of pathways to children hospitalized with asthma.

Iterative Adaptation of a Tuberculosis Digital Medication Adherence Technology to Meet User Needs: Qualitative Study of Patients and Health Care Providers Using Human-Centered Design Methods.

BACKGROUND: Digital adherence technologies have been widely promoted as a means to improve tuberculosis medication adherence. However, uptake of these technologies has been suboptimal by both patients and health workers. Not surprisingly, studies have not demonstrated significant improvement in treatment outcomes. OBJECTIVE: This study aimed to optimize a well-known digital adherence technology, 99DOTS, for end user needs in Uganda. We describe the findings of the ideation phase of the human-centered design methodology to adapt 99DOTS according to a set of design principles identified in the previous inspiration phase. METHODS: 99DOTS is a low-cost digital adherence technology wherein tuberculosis medication blister packs are encased within an envelope that reveals toll-free numbers that patients can call to report dosing. We identified 2 key areas for design and testing: (1) the envelope, including the form factor, content, and depiction of the order of pill taking; and (2) the patient call-in experience. We conducted 5 brainstorming sessions with all relevant stakeholders to generate a suite of potential prototype concepts. Senior investigators identified concepts to further develop based on feasibility and consistency with the predetermined design principles. Prototypes were revised with feedback from the entire team. The envelope and call-in experience prototypes were tested and iteratively revised through focus groups with health workers (n=52) and interviews with patients (n=7). We collected and analyzed qualitative feedback to inform each subsequent iteration. RESULTS: The 5 brainstorming sessions produced 127 unique ideas that we clustered into 6 themes: rewards, customization, education, logistics, wording and imagery, and treatment countdown. We developed 16 envelope prototypes, 12 icons, and 28 audio messages for prototype testing. In the final design, we altered the pill packaging envelope by adding a front flap to conceal the pills and reduce potential stigma associated with tuberculosis. The flap was adorned with either a blank calendar or map of Uganda. The inside cover contained a personalized message from a local health worker including contact information, pictorial pill-taking instructions, and a choice of stickers to tailor education to the patient and phase of treatment. Pill-taking order was indicated with colors, chevron arrows, and small mobile phone icons. Last, the call-in experience when patients report dosing was changed to a rotating series of audio messages centered on the themes of prevention, encouragement, and reassurance that tuberculosis is curable. CONCLUSIONS: We demonstrated the use of human-centered design as a promising tool to drive the adaptation of digital adherence technologies to better address the needs and motivations of end users. The next phase of research, known as the implementation phase in the human-centered design methodology, will investigate whether the adapted 99DOTS platform results in higher levels of engagement from patients and health workers, and ultimately improves tuberculosis treatment outcomes.

Patient and health system factors associated with pretreatment loss to follow up among patients diagnosed with tuberculosis using Xpert® MTB/RIF testing in Uganda.

BACKGROUND: In 2018, Uganda started only 65% of persons with incident tuberculosis on treatment. Pretreatment loss to follow up is an important contributor to suboptimal treatment coverage. We aimed to describe the patient and health facility-level characteristics associated with pretreatment loss to follow up among patients diagnosed with pulmonary tuberculosis at public health facilities in Uganda. METHODS: At ten public health facilities, laboratory register data was used to identify patients aged ≥ 15 years who had a positive Xpert®MTB/RIF test. Initiation on TB treatment was ascertained using the clinical register. Factors associated with not being initiated on TB treatment within two weeks of diagnosis were examined using a multilevel logistic regression model accounting for clustering by health facility. RESULTS: From January to June 2018, 510 patients (61.2% male and 31.5% HIV co-infected) were diagnosed with tuberculosis. One hundred (19.6%) were not initiated on TB treatment within 2 weeks of diagnosis. Not having a phone number recorded in the clinic registers (aOR 7.93, 95%CI 3.93-13.05); being HIV-infected (aOR 1.83; 95% CI: 1.09-3.26) and receiving care from a high volume health facility performing more than 12 Xpert tests per day (aOR 4.37, 95%CI 1.69-11.29) and were significantly associated with pretreatment loss to follow up. CONCLUSION: In public health facilities in Uganda, we found a high rate of pretreatment loss to follow up especially among TBHIV co-infected patients diagnosed at high volume health facilities. Interventions to improve the efficiency of Xpert® MTB/RIF testing, including monitoring of the TB care cascade should be developed and implemented.

Costs incurred by patients with drug-susceptible pulmonary tuberculosis in semi-urban and rural settings of Western India.

BACKGROUND: India reports the highest number of tuberculosis (TB) cases worldwide. Poverty has a dual impact as it increases the risk of TB and exposes the poor to economic hardship when they develop TB. Our objective was to estimate the costs incurred by patients with drug-susceptible TB in Bhavnagar (western India) using an adapted World Health Organization costing tool. METHODS: We conducted a descriptive cross-sectional study of adults, notified in the public sector and being treated for drug-susceptible pulmonary TB during January-June 2019, in six urban and three rural blocks of Bhavnagar region, Gujarat state, India. The direct and indirect TB-related costs, as well as patients' coping strategies, were assessed for the overall care of TB till treatment completion. Catastrophic costs were defined as total costs > 20% of annual household income (excluding any amount received from cash transfer programs or borrowed). Median and interquartile range (IQR) was used to summarize patient costs. The median costs between any two groups were compared using the median test. The association between any two categorical variables was tested by the Pearson chi-squared test. All costs were described in US dollars (USD). During the study period, on average, one USD equalled 70 Indian Rupees. RESULTS: Of 458 patients included, 70% were male, 62% had no formal education, 71% lived in urban areas, and 96% completed TB treatment. The median (IQR) total costs were USD 8 (5-28), direct medical costs were USD 0 (0-0), direct non-medical costs were USD 3 (2-4) and indirect costs were USD 6 (3-13). Among direct non-medical costs, travel cost (median = USD 3, IQR: 2-4) to attend health facilities were the most prominent, whereas the indirect costs were mainly contributed by the patient's loss of wages (median = USD 3, IQR: 0-6). Four percent of patients faced catastrophic costs, 11% borrowed money to cover costs and 7% lost their employment; the median working days lost to TB was 30 (IQR: 15-45). A majority (88%) of patients received a median USD 43 (IQR: 41-43) as part of a cash transfer program for TB patients. CONCLUSIONS: Treatment completion was high and the costs incurred by TB patients were low in this setting. However, negative financial consequences occur even in low-cost settings. The role of universal cash transfer programs in such settings requires further study.

Guidance for Studies Evaluating the Accuracy of Tuberculosis Triage Tests.

Approximately 3.6 million cases of active tuberculosis (TB) go potentially undiagnosed annually, partly due to limited access to confirmatory diagnostic tests, such as molecular assays or mycobacterial culture, in community and primary healthcare settings. This article provides guidance for TB triage test evaluations. A TB triage test is designed for use in people with TB symptoms and/or significant risk factors for TB. Triage tests are simple and low-cost tests aiming to improve ease of access and implementation (compared with confirmatory tests) and decrease the proportion of patients requiring more expensive confirmatory testing. Evaluation of triage tests should occur in settings of intended use, such as community and primary healthcare centers. Important considerations for triage test evaluation include study design, population, sample type, test throughput, use of thresholds, reference standard (ideally culture), and specimen flow. The impact of a triage test will depend heavily on issues beyond accuracy, primarily centered on implementation.

Outlook for tuberculosis elimination in California: An individual-based stochastic model.

RATIONALE: As part of the End TB Strategy, the World Health Organization calls for low-tuberculosis (TB) incidence settings to achieve pre-elimination (<10 cases per million) and elimination (<1 case per million) by 2035 and 2050, respectively. These targets require testing and treatment for latent tuberculosis infection (LTBI). OBJECTIVES: To estimate the ability and costs of testing and treatment for LTBI to reach pre-elimination and elimination targets in California. METHODS: We created an individual-based epidemic model of TB, calibrated to historical cases. We evaluated the effects of increased testing (QuantiFERON-TB Gold) and treatment (three months of isoniazid and rifapentine). We analyzed four test and treat targeting strategies: (1) individuals with medical risk factors (MRF), (2) non-USB, (3) both non-USB and MRF, and (4) all Californians. For each strategy, we estimated the effects of increasing test and treat by a factor of 2, 4, or 10 from the base case. We estimated the number of TB cases occurring and prevented, and net and incremental costs from 2017 to 2065 in 2015 U.S. dollars. Efficacy, costs, adverse events, and treatment dropout were estimated from published data. We estimated the cost per case averted and per quality-adjusted life year (QALY) gained. MEASUREMENTS AND MAIN RESULTS: In the base case, 106,000 TB cases are predicted to 2065. Pre-elimination was achieved by 2065 in three scenarios: a 10-fold increase in the non-USB and persons with MRF (by 2052), and 4- or 10-fold increase in all Californians (by 2058 and 2035, respectively). TB elimination was not achieved by any intervention scenario. The most aggressive strategy, 10-fold in all Californians, achieved a case rate of 8 (95% UI 4-16) per million by 2050. Of scenarios that reached pre-elimination, the incremental net cost was $20 billion (non-USB and MRF) to $48 billion. These had an incremental cost per QALY of $657,000 to $3.1 million. A more efficient but somewhat less effective single-lifetime test strategy reached as low as $80,000 per QALY. CONCLUSIONS: Substantial gains can be made in TB control in coming years by scaling-up current testing and treatment in non-USB and those with medical risks.

Yield and Efficiency of Novel Intensified Tuberculosis Case-Finding Algorithms for People Living with HIV.

RATIONALE: The recommended tuberculosis (TB) intensified case finding (ICF) algorithm for people living with HIV (symptom-based screening followed by Xpert MTB/RIF [Xpert] testing) is insufficiently sensitive and results in unnecessary Xpert testing. OBJECTIVES: To evaluate whether novel ICF algorithms combining C-reactive protein (CRP)-based screening with urine Determine TB-LAM (TB-LAM), sputum Xpert, and/or sputum culture could improve ICF yield and efficiency. METHODS: We compared the yield and efficiency of novel ICF algorithms inclusive of point-of-care CRP-based TB screening and confirmatory testing with urine TB-LAM (if CD4 count ≤100 cells/µl), sputum Xpert, and/or a single sputum culture among consecutive people living with HIV with CD4 counts less than or equal to 350 cells/µl initiating antiretroviral therapy in Uganda. MEASUREMENTS AND MAIN RESULTS: Of 1,245 people living with HIV, 203 (16%) had culture-confirmed TB including 101 (49%) patients with CD4 counts less than or equal to 100 cells/µl. Compared with the current ICF algorithm, point-of-care CRP-based TB screening followed by Xpert testing had similar yield (56% [95% confidence interval, 49-63] vs. 59% [95% confidence interval, 51-65]) but consumed less than half as many Xpert assays per TB case detected (9 vs. 4). Addition of TB-LAM did not significantly increase diagnostic yield relative to the current ICF algorithm but provided same-day diagnosis for 26% of TB patients with advanced HIV. Addition of a single culture to TB-LAM and Xpert substantially improved ICF yield, identifying 78% of all TB cases. CONCLUSIONS: Point-of-care CRP-based screening can improve ICF efficiency among people living with HIV. Addition of TB-LAM and a single culture to Xpert confirmatory testing could enable HIV programs to increase the speed of TB diagnosis and ICF yield.

Effectiveness-implementation of COPD case finding and self-management action plans in low- and middle-income countries: global excellence in COPD outcomes (GECo) study protocol.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the end result of a susceptible individual being exposed to sufficiently deleterious environmental stimuli. More than 90% of COPD-related deaths occur in low- and middle-income countries (LMICs). LMICs face unique challenges in managing COPD; for example, deficient primary care systems present challenges for proper diagnosis and management. Formal diagnosis of COPD requires quality-assured spirometry, which is often limited to urban health centres. Similarly, standard treatment options for COPD remain limited where few providers are trained to manage COPD. The Global Excellence in COPD Outcomes (GECo) studies aim to assess the performance of a COPD case-finding questionnaire with and without peak expiratory flow (PEF) to diagnose COPD, and inform the effectiveness and implementation of COPD self-management Action Plans in LMIC settings. The ultimate goal is to develop simple, low-cost models of care that can be implemented in LMICs. This study will be carried out in Nepal, Peru and Uganda, three distinct LMIC settings. METHODS/DESIGN: We aim to assess the diagnostic accuracy of a simple questionnaire with and without PEF to case-find COPD (GECo1), and examine the effectiveness, cost-effectiveness and implementation of a community-health-worker-supported self-management Action Plan strategy for managing exacerbations of COPD (GECo2). To achieve the first aim, we will enrol a randomly selected sample of up to 10,500 adults aged ≥ 40 years across our three sites, with the goal to enrol 240 participants with moderate-to-severe COPD in to GECo2. We will apply two case-finding questionnaires (Lung Function Questionnaire and CAPTURE) with and without PEF and compare performance against spirometry. We will report ROC areas, sensitivity and specificity. Individuals who are identified as having COPD grades B-D will be invited to enrol in an effectiveness-implementation hybrid randomised trial of a multi-faceted COPD self-management Action Plan intervention delivered by CHWs. The intervention group will receive (1) COPD education, (2) facilitated-self management Action Plans for COPD exacerbations and (3) monthly visits by community health workers. The control group will receive COPD education and standard of care treatment provided by local health providers. Beginning at baseline, we will measure quality of life with the EuroQol-5D (EQ-5D) and St. George's Respiratory Questionnaire (SGRQ) every 3 months over a period of 1 year. The primary endpoint is SGRQ at 12 months. Quality-adjusted life years (QALYs) using the Short-Form 36 version 2 will also be calculated. We will additionally assess the acceptability and feasibility of implementing COPD Action Plans in each setting among providers and individuals with COPD. DISCUSSION: This study should provide evidence to inform the use of pragmatic models of COPD diagnosis and management in LMIC settings. TRIAL REGISTRATION: NCT03359915 (GECo1). Registered on 2 December 2017 and NCT03365713 (GECo2). Registered on 7 December 2017. Trial acronym: Global Excellence in COPD Outcomes (GECo1; GECo2).

Serial testing for latent tuberculosis using QuantiFERON-TB Gold In-Tube: A Markov model.

Healthcare workers (HCWs) in low-incidence settings are often serially tested for latent TB infection (LTBI) with the QuantiFERON-TB Gold In-Tube (QFT) assay, which exhibits frequent conversions and reversions. The clinical impact of such variability on serial testing remains unknown. We used a microsimulation Markov model that accounts for major sources of variability to project diagnostic outcomes in a simulated North American HCW cohort. Serial testing using a single QFT with the recommended conversion cutoff (IFN-g > 0.35 IU/mL) resulted in 24.6% (95% uncertainty range, UR: 23.8-25.5) of the entire population testing false-positive over ten years. Raising the cutoff to >1.0 IU/mL or confirming initial positive results with a (presumed independent) second test reduced this false-positive percentage to 2.3% (95%UR: 2.0-2.6%) or 4.1% (95%UR: 3.7-4.5%), but also reduced the proportion of true incident infections detected within the first year of infection from 76.5% (95%UR: 66.3-84.6%) to 54.8% (95%UR: 44.6-64.5%) or 61.5% (95%UR: 51.6-70.9%), respectively. Serial QFT testing of HCWs in North America may result in tremendous over-diagnosis and over-treatment of LTBI, with nearly thirty false-positives for every true infection diagnosed. Using higher cutoffs for conversion or confirmatory tests (for initial positives) can mitigate these effects, but will also diagnose fewer true infections.

Cost-effectiveness of triage testing for facility-based systematic screening of tuberculosis among Ugandan adults.

BACKGROUND: Systematic screening is often proposed as a way to improve case finding for tuberculosis (TB), but the cost-effectiveness of specific strategies for systematic screening remains poorly studied. METHODS: We constructed a Markov-based decision analytic model to analyse the cost-effectiveness of triage testing for TB in Uganda, compared against passive case detection with Xpert MTB/RIF. We assumed a triage algorithm whereby all adults presenting to healthcare centres would be screened for cough, and those with cough of at least 2 weeks would receive the triage test, with positive triage results confirmed by Xpert MTB/RIF. We adopted the perspective of the TB control sector, using a primary outcome of the cost per year of life gained (YLG) over a lifetime time horizon. RESULTS: Systematic screening in a population with a 5% underlying prevalence of TB was estimated to cost US$610 per YLG (95% uncertainty range US$200-US$1859) with chest X-ray (CXR) (US$5 per test, specificity 0.67), or US$588 (US$221-US$1746) with C reactive protein (CRP) (US$3 per test, specificity 0.59). In addition to the cost and specificity of the triage test, cost-effectiveness was most sensitive to the underlying prevalence of TB, monthly risk of mortality in people with untreated TB and the proportion of patients with TB who would be treated in the absence of systematic screening. CONCLUSIONS: To optimise the cost-effectiveness of facility-based systematic screening of TB with a triage test, it must be carried out in a high-risk population, or use triage tests that are cheaper or more specific than CXR or CRP.

Health worker perspectives on barriers to delivery of routine tuberculosis diagnostic evaluation services in Uganda: a qualitative study to guide clinic-based interventions.

BACKGROUND: Studies of the quality of tuberculosis (TB) diagnostic evaluation of patients in high burden countries have generally shown poor adherence to international or national guidelines. Health worker perspectives on barriers to improving TB diagnostic evaluation are critical for developing clinic-level interventions to improve guideline implementation. METHODS: We conducted structured, in-depth interviews with staff at six district-level health centers in Uganda to elicit their perceptions regarding barriers to TB evaluation. Interviews were transcribed, coded with a standardized framework, and analyzed to identify emergent themes. We used thematic analysis to develop a logic model depicting health system and contextual barriers to recommended TB evaluation practices. To identify possible clinic-level interventions to improve TB evaluation, we categorized findings into predisposing, enabling, and reinforcing factors as described by the PRECEDE model, focusing on potentially modifiable behaviors at the clinic-level. RESULTS: We interviewed 22 health center staff between February 2010 and November 2011. Participants identified key health system barriers hindering TB evaluation, including: stock-outs of drugs/supplies, inadequate space and infrastructure, lack of training, high workload, low staff motivation, and poor coordination of health center services. Contextual barrier challenges to TB evaluation were also reported, including the time and costs borne by patients to seek and complete TB evaluation, poor health literacy, and stigma against patients with TB. These contextual barriers interacted with health system barriers to contribute to sub-standard TB evaluation. Examples of intervention strategies that could address these barriers and are related to PRECEDE model components include: assigned mentors/peer coaching for new staff (targets predisposing factor of low motivation and need for support to conduct job duties); facilitated workshops to implement same day microscopy (targets enabling factor of patient barriers to completing TB evaluation), and recognition/incentives for good TB screening practices (targets low motivation and self-efficacy). CONCLUSIONS: Our findings suggest that health system and contextual barriers work together to impede TB diagnosis at health centers and, if not addressed, could hinder TB case detection efforts. Qualitative research that improves understanding of the barriers facing TB providers is critical to developing targeted interventions to improve TB care.