Which attributes within target product profiles for tuberculosis diagnostics are the most important to focus on?

Involving patients in drug development for Neglected Tropical Diseases (NTDs): A qualitative study exploring and incorporating preferences of patients with cutaneous leishmaniasis into Target Product Profile development

BACKGROUND

Target Product Profiles (TPPs) are instrumental to help optimise the design and development of therapeutics, vaccines, and diagnostics - these products, in order to achieve the intended impact, should be aligned with users' preferences and needs. However, patients are rarely involved as key stakeholders in building a TPP.

METHODOLOGY

Thirty-three cutaneous leishmaniasis (CL) patients from Brazil, Colombia, and Austria, infected with New-World Leishmania species, were recruited using a maximum variation approach along geographic, sociodemographic and clinical criteria. Semi-structured interviews were conducted in the respective patient's mother tongue. Transcripts, translated into English, were analysed using a framework approach. We matched disease experiences, preferences, and expectations of CL patients to a TPP developed by DNDi (Drug for Neglected Diseases initiative) for CL treatment.

PRINCIPAL FINDINGS

Patients' preferences regarding treatments ranged from specific efficacy and safety endpoints to direct and significant indirect costs. Respondents expressed views about trade-offs between efficacy and experienced discomfort/adverse events caused by treatment. Reasons for non-compliance, such as adverse events or geographical and availability barriers, were discussed. Considerations related to accessibility and affordability were relevant from the patients' perspective.

CONCLUSIONS/SIGNIFICANCE

NTDs affect disadvantaged populations, often with little access to health systems. Engaging patients in designing adapted therapies could significantly contribute to the suitability of an intervention to a specific context and to compliance, by tailoring the product to the end-users' needs. This exploratory study identified preferences in a broad international patient spectrum. It provides methodological guidance on how patients can be meaningfully involved as stakeholders in the construction of a TPP of therapeutics for NTDs. CL is used as an exemplar, but the approach can be adapted for other NTDs.

Rapid molecular tests for tuberculosis and tuberculosis drug resistance: a qualitative evidence synthesis of recipient and provider views

BACKGROUND

Programmes that introduce rapid molecular tests for tuberculosis and tuberculosis drug resistance aim to bring tests closer to the community, and thereby cut delay in diagnosis, ensure early treatment, and improve health outcomes, as well as overcome problems with poor laboratory infrastructure and inadequately trained personnel. Yet, diagnostic technologies only have an impact if they are put to use in a correct and timely manner. Views of the intended beneficiaries are important in uptake of diagnostics, and their effective use also depends on those implementing testing programmes, including providers, laboratory professionals, and staff in health ministries. Otherwise, there is a risk these technologies will not fit their intended use and setting, cannot be made to work and scale up, and are not used by, or not accessible to, those in need.

OBJECTIVES

To synthesize end-user and professional user perspectives and experiences with low-complexity nucleic acid amplification tests (NAATs) for detection of tuberculosis and tuberculosis drug resistance; and to identify implications for effective implementation and health equity.

SEARCH METHODS

We searched MEDLINE, Embase, CINAHL, PsycInfo and Science Citation Index Expanded databases for eligible studies from 1 January 2007 up to 20 October 2021. We limited all searches to 2007 onward because the development of Xpert MTB/RIF, the first rapid molecular test in this review, was completed in 2009.

SELECTION CRITERIA

We included studies that used qualitative methods for data collection and analysis, and were focused on perspectives and experiences of users and potential users of low-complexity NAATs to diagnose tuberculosis and drug-resistant tuberculosis. NAATs included Xpert MTB/RIF, Xpert MTB/RIF Ultra, Xpert MTB/XDR, and the Truenat assays. Users were people with presumptive or confirmed tuberculosis and drug-resistant tuberculosis (including multidrug-resistant (MDR-TB)) and their caregivers, healthcare providers, laboratory technicians and managers, and programme officers and staff; and were from any type of health facility and setting globally. MDR-TB is tuberculosis caused by resistance to at least rifampicin and isoniazid, the two most effective first-line drugs used to treat tuberculosis.

DATA COLLECTION AND ANALYSIS

We used a thematic analysis approach for data extraction and synthesis, and assessed confidence in the findings using GRADE CERQual approach. We developed a conceptual framework to illustrate how the findings relate.

MAIN RESULTS

We found 32 studies. All studies were conducted in low- and middle-income countries. Twenty-seven studies were conducted in high-tuberculosis burden countries and 21 studies in high-MDR-TB burden countries. Only one study was from an Eastern European country. While the studies covered a diverse use of low-complexity NAATs, in only a minority of studies was it used as the initial diagnostic test for all people with presumptive tuberculosis. We identified 18 review findings and grouped them into three overarching categories. Critical aspects users value People with tuberculosis valued reaching diagnostic closure with an accurate diagnosis, avoiding diagnostic delays, and keeping diagnostic-associated cost low. Similarly, healthcare providers valued aspects of accuracy and the resulting confidence in low-complexity NAAT results, rapid turnaround times, and keeping cost to people seeking a diagnosis low. In addition, providers valued diversity of sample types (for example, gastric aspirate specimens and stool in children) and drug resistance information. Laboratory professionals appreciated the improved ease of use, ergonomics, and biosafety of low-complexity NAATs compared to sputum microscopy, and increased staff satisfaction. Challenges reported to realizing those values People with tuberculosis and healthcare workers were reluctant to test for tuberculosis (including MDR-TB) due to fears, stigma, or cost concerns. Thus, low-complexity NAAT testing is not implemented with sufficient support or discretion to overcome barriers that are common to other approaches to testing for tuberculosis. Delays were reported at many steps of the diagnostic pathway owing to poor sample quality; difficulties with transporting specimens; lack of sufficient resources; maintenance of low-complexity NAATs; increased workload; inefficient work and patient flows; over-reliance on low-complexity NAAT results in lieu of clinical judgement; and lack of data-driven and inclusive implementation processes. These challenges were reported to lead to underutilization.  Concerns for access and equity The reported concerns included sustainable funding and maintenance and equitable use of resources to access low-complexity NAATs, as well as conflicts of interest between donors and people implementing the tests. Also, lengthy diagnostic delays, underutilization of low-complexity NAATs, lack of tuberculosis diagnostic facilities in the community, and too many eligibility restrictions hampered access to prompt and accurate testing and treatment. This was particularly the case for vulnerable groups, such as children, people with MDR-TB, or people with limited ability to pay. We had high confidence in most of our findings.

AUTHORS' CONCLUSIONS

Low-complexity diagnostics have been presented as a solution to overcome deficiencies in laboratory infrastructure and lack of skilled professionals. This review indicates this is misleading. The lack of infrastructure and human resources undermine the added value new diagnostics of low complexity have for recipients and providers. We had high confidence in the evidence contributing to these review findings. Implementation of new diagnostic technologies, like those considered in this review, will need to tackle the challenges identified in this review including weak infrastructure and systems, and insufficient data on ground level realities prior and during implementation, as well as problems of conflicts of interest in order to ensure equitable use of resources.

Aligning diagnostics to the point-of-care: lessons for innovators, evaluators and decision-makers from tuberculosis and HIV

Diagnostics, including those that work at point-of-care, are an essential part of successful public health responses to infectious diseases and pandemics. Yet, they are not always used or fit intended use settings. This paper reports on key insights from a qualitative study on how those engaged with developing and implementing new point-of-care (POC) diagnostics for tuberculosis (TB) and HIV ensure these technologies work at POC. Ethnographic fieldwork between 2015 and 2017 consisting of 53 semistructured interviews with global stakeholders and visits to workshops, companies, and conferences was combined with 15 semistructured interviews with stakeholders in India including providers, decision-makers, scientists and developers and visits to companies, clinics and laboratories. Our results show how developers and implementer of HIV and TB POC diagnostics aim to know and align their diagnostics to elements in more settings than just intended use, but also the setting of the developer, the global intermediaries, the bug/disease and the competitor. Actors and elements across these five settings define what a good diagnostic is, yet their needs might conflict or change and they are difficult to access. Aligning diagnostics to the POC requires continuous needs assessment throughout development and implementation phases as well as substantive, ongoing investment in relationships with users. The flexibility required for such continuous realigning and iteration clashes with established evaluation procedures and business models in global health and risks favouring certain products over others. The paper concludes with suggestions to strengthen this alignment work and applies this framework to research needs in the wake of COVID-19.

Valuing Simplicity: Developing a Good Point of Care Diagnostic

Point-of-care testing promises laboratory-based precision in settings that do not have easy access to laboratories or where processing tests takes too long or is too costly. Developers and global health actors stress values and norms such as simplicity, rapidity and accuracy for realizing diagnostic innovations that work at point of care and are aligned to the specific requirements of point-of-care settings. This paper uses fieldwork among diagnostic manufacturers, scientists, donors, members of civil society, industry consultants, international organizations, regulators, policymakers, programme officers, lab technicians, and clinicians involved in development and implementation of tuberculosis and HIV diagnostics, to examine how norms and values of what constitutes a good point-of-care diagnostic are operating in practice through both top-down and bottom-up dynamics. It draws the link between design, evidence and adoption of diagnostics and how the different actors interpret the values underpinning the new practice. The analysis draws on literature on valuation practices, evidence-making and technology design in science and technology studies and medical sociology. The findings reveal how these values constitute innovation, implementation, and evaluation practices across global and local (India) sites, with important consequences for funding of health infrastructure, capacity, and training resources for addressing some of the existing structural inequalities. Dominant values currently defining point of care diagnostics risk exacerbating health inequalities between those who do and do not have the necessary social and financial resources to access better equipped and functioning healthcare facilities, especially in resource constrained settings.

Guidance for Studies Evaluating the Accuracy of Sputum-Based Tests to Diagnose Tuberculosis

Tests that can replace sputum smear microscopy have been identified as a top priority diagnostic need for tuberculosis by the World Health Organization. High-quality evidence on diagnostic accuracy for tests that may meet this need is an essential requirement to inform decisions about policy and scale-up. However, test accuracy studies are often of low and inconsistent quality and poorly reported, leading to uncertainty about true test performance. Here we provide guidance for the design of diagnostic test accuracy studies of sputum smear-replacement tests. Such studies should have a cross-sectional or cohort design, enrolling either a consecutive series or a random sample of patients who require evaluation for tuberculosis. Adults with respiratory symptoms are the target population. The reference standard should at a minimum be a single, automated, liquid culture, but additional cultures, follow-up, clinical case definition, and specific measures to understand discordant results should also be included. Inclusion of smear microscopy and Xpert MTB/RIF (or MTB/RIF Ultra) as comparators is critical to allow broader comparability and generalizability of results, because disease spectrum can vary between studies and affects relative test performance. Given the complex nature of sputum (the primary specimen type used for pulmonary TB), careful design and reporting of the specimen flow is essential. Test characteristics other than accuracy (such as feasibility, implementation considerations, and data on impact on patient, population and health systems outcomes) are also important aspects.