From biomarkers to medical tests: the changing landscape of test evaluation

Outcome-based analytical performance specifications: current status and future challenges

Analytical performance specifications (APS) based on outcomes refer to how 'good' the analytical performance of a test needs to be to do more good than harm to the patient. Analytical performance of a measurand affects its clinical performance. Without first setting clinical performance requirements, it is difficult to define how good analytically the test needs to be to meet medical needs. As testing is indirectly linked to health outcomes through clinical decisions on patient management, often simulation-based studies are used to assess the impact of analytical performance on the probability of clinical outcomes which is then translated to Model 1b APS according to the Milan consensus. This paper discusses the related key definitions, concepts and considerations that should assist in finding the most appropriate methods for deriving Model 1b APS. We review the advantages and limitations of published methods and discuss the criteria for transferability of Model 1b APS to different settings. We consider that the definition of the clinically acceptable misclassification rate is central to Model 1b APS. We provide some examples and guidance on a more systematic approach for first defining the clinical performance requirements for tests and we also highlight a few ideas to tackle the future challenges associated with providing outcome-based APS for laboratory testing.

Advances in research on biomarkers associated with acute myocardial infarction: A review

Acute myocardial infarction (AMI), the most severe cardiovascular event in clinical settings, imposes a significant burden with its annual increase in morbidity and mortality rates. However, it is noteworthy that mortality due to AMI in developed countries has experienced a decline, largely attributable to the advancements in medical interventions such as percutaneous coronary intervention. This trend highlights the importance of accurate diagnosis and effective treatment to preserve the myocardium at risk and improve patient outcomes. Conventional biomarkers such as myoglobin, creatine kinase isoenzymes, and troponin have been instrumental in the diagnosis of AMI. However, recent years have witnessed the emergence of new biomarkers demonstrating the potential to further enhance the accuracy of AMI diagnosis. This literature review focuses on the recent advancements in biomarker research in the context of AMI diagnosis.

Acceptability of magnetic resonance imaging for prostate cancer diagnosis with patients and GPs: a qualitative interview study

BACKGROUND

Magnetic resonance imaging (MRI) of the prostate is a new, more accurate, non-invasive test for prostate cancer diagnosis.

AIM

To understand the acceptability of MRI for patients and GPs for prostate cancer diagnosis.

DESIGN AND SETTING

Qualitative study of men who had undergone a prostate MRI for possible prostate cancer, and GPs who had referred at least one man for possible prostate cancer in the previous 12 months in West London and Devon.

METHOD

Semi-structured interviews, conducted in person or via telephone, were audio-recorded and transcribed verbatim. Deductive thematic analysis was undertaken using Sekhon's Theoretical Framework of Acceptability, retrospectively for patients and prospectively for GPs.

RESULTS

Twenty-two men (12 from Devon, age range 47-80 years), two patients' partners, and 10 GPs (6 female, age range 36-55 years) were interviewed. Prostate MRI was broadly acceptable for most patient participants, and they reported that it was not a significant undertaking to complete the scan. GPs were more varied in their views on prostate MRI, with a broad spectrum of knowledge and understanding of prostate MRI. Some GPs expressed concerns about additional clinical responsibility and local availability of MRI if direct access to prostate MRI in primary care were to be introduced.

CONCLUSION

Prostate MRI appears to be acceptable to patients. Some differences were found between patients in London and Devon, mainly around burden of testing and opportunity costs. Further exploration of GPs' knowledge and understanding of prostate MRI could inform future initiatives to widen access to diagnostic testing in primary care.

Point-of-Care Lung Ultrasound in Emergency Medicine: A Scoping Review With an Interactive Database

BACKGROUND

This scoping review was conducted to provide an overview of the evidence of point-of-care lung ultrasound (LUS) in emergency medicine. By emphasizing clinical topics, time trends, study designs, and the scope of the primary outcomes, a map is provided for physicians and researchers to guide their future initiatives.

RESEARCH QUESTION

Which study designs and primary outcomes are reported in published studies of LUS in emergency medicine?

STUDY DESIGN AND METHODS

We performed a systematic search in the PubMed/MEDLINE, Embase, Web of Science, Scopus, and Cochrane Library databases for LUS studies published prior to May 13, 2023. Study characteristics were synthesized quantitatively. The primary outcomes in all papers were categorized into the hierarchical Fryback and Thornbury levels.

RESULTS

A total of 4,076 papers were screened and, following selection and handsearching, 406 papers were included. The number of publications doubled from January 2020 to May 2023 (204 to 406 papers). The study designs were primarily observational (n = 375 [92%]), followed by randomized (n = 18 [4%]) and case series (n = 13 [3%]). The primary outcome measure concerned diagnostic accuracy in 319 papers (79%), diagnostic thinking in 32 (8%), therapeutic changes in 4 (1%), and patient outcomes in 14 (3%). No increase in the proportions of randomized controlled trials or the scope of primary outcome measures was observed with time. A freely available interactive database was created to enable readers to search for any given interest (https://public.tableau.com/app/profile/blinded/viz/LUSinEM_240216/INFO).

INTERPRETATION

Observational diagnostic studies have been produced in abundance, leaving a paucity of research exploring clinical utility. Notably, research exploring whether LUS causes changes to clinical decisions is imperative prior to any further research being made into patient benefits.

Closing the gaps in patient management of dyslipidemia: stepping into cardiovascular precision diagnostics with apolipoprotein profiling

In persons with dyslipidemia, a high residual risk of cardiovascular disease remains despite lipid lowering therapy. Current cardiovascular risk prediction mainly focuses on low-density lipoprotein cholesterol (LDL-c) levels, neglecting other contributing risk factors. Moreover, the efficacy of LDL-c lowering by statins resulting in reduced cardiovascular risk is only partially effective. Secondly, from a metrological viewpoint LDL-c falls short as a reliable measurand. Both direct and calculated LDL-c tests produce inaccurate test results at the low end under aggressive lipid lowering therapy. As LDL-c tests underperform both clinically and metrologically, there is an urging need for molecularly defined biomarkers. Over the years, apolipoproteins have emerged as promising biomarkers in the context of cardiovascular disease as they are the functional workhorses in lipid metabolism. Among these, apolipoprotein B (ApoB), present on all atherogenic lipoprotein particles, has demonstrated to clinically outperform LDL-c. Other apolipoproteins, such as Apo(a) - the characteristic apolipoprotein of the emerging risk factor lipoprotein(a) -, and ApoC-III - an inhibitor of triglyceride-rich lipoprotein clearance -, have attracted attention as well. To support personalized medicine, we need to move to molecularly defined risk markers, like the apolipoproteins. Molecularly defined diagnosis and molecularly targeted therapy require molecularly measured biomarkers. This review provides a summary of the scientific validity and (patho)physiological role of nine serum apolipoproteins, Apo(a), ApoB, ApoC-I, ApoC-II, ApoC-III, ApoE and its phenotypes, ApoA-I, ApoA-II, and ApoA-IV, in lipid metabolism, their association with cardiovascular disease, and their potential as cardiovascular risk markers when measured in a multiplex apolipoprotein panel.

Expert guidance on target product profile development for AMR diagnostic tests

Diagnostics are widely considered crucial in the fight against antimicrobial resistance (AMR), which is expected to kill 10 million people annually by 2030. Nevertheless, there remains a substantial gap between the need for AMR diagnostics versus their development and implementation. To help address this problem, target product profiles (TPP) have been developed to focus developers' attention on the key aspects of AMR diagnostic tests. However, during discussion between a multisectoral working group of 51 international experts from industry, academia and healthcare, it was noted that specific AMR-related TPPs could be extended by incorporating the interdependencies between the key characteristics associated with the development of such TPPs. Subsequently, the working group identified 46 characteristics associated with six main categories (ie, Intended Use, Diagnostic Question, Test Description, Assay Protocol, Performance and Commercial). The interdependencies of these characteristics were then identified and mapped against each other to generate new insights for use by stakeholders. Specifically, it may not be possible for diagnostics developers to achieve all of the recommendations in every category of a TPP and this publication indicates how prioritising specific TPP characteristics during diagnostics development may influence (or not) a range of other TPP characteristics associated with the diagnostic. The use of such guidance, in conjunction with specific TPPs, could lead to more efficient AMR diagnostics development.

Toolkit for emerging technologies in laboratory medicine

An emerging technology (ET) for laboratory medicine can be defined as an analytical method (including biomarkers) or device (software, applications, and algorithms) that by its stage of development, translation into broad routine clinical practice, or geographical adoption and implementation has the potential to add value to clinical diagnostics. Considering the laboratory medicine-specific definition, this document examines eight key tools, encompassing clinical, analytical, operational, and financial aspects, used throughout the life cycle of ET implementation. The tools provide a systematic approach starting with identifying the unmet need or identifying opportunities for improvement (Tool 1), forecasting (Tool 2), technology readiness assessment (Tool 3), health technology assessment (Tool 4), organizational impact map (Tool 5), change management (Tool 6), total pathway to method evaluation checklist (Tool 7), and green procurement (Tool 8). Whilst there are differences in clinical priorities between different settings, the use of this set of tools will help support the overall quality and sustainability of the emerging technology implementation.

Clinical utility - Information about the usefulness of tests

The clinical utility of a diagnostic test refers to its usefulness in improving patient outcomes, informing clinical decision-making, and optimizing healthcare resources. A diagnostic test with high clinical utility provides accurate, reliable, and actionable information that can guide appropriate treatment decisions, monitor treatment response, and identify potential adverse events or complications. Ultimately, the clinical utility of a diagnostic test depends on how well it can improve patient outcomes by guiding appropriate treatment decisions, improving clinical outcomes, and optimizing healthcare resource utilization. Healthcare providers need to weigh the benefits and drawbacks of using a particular diagnostic test in their clinical practice to determine its clinical utility.

Methods for determining clinical utility

Measuring the clinical utility of a diagnostic test involves evaluating its impact on patient outcomes, clinical decision-making, and healthcare resource utilization. Determining clinical utility requires accessing patient medical history and outcomes data. These studies involve enrolling patients undergoing diagnostic tests and tracking their clinical outcomes. Researchers can determine the test's clinical utility by comparing the outcomes of patients who receive the diagnostic test to those who do not. These outcomes include benefits and harm. The highest level of evidence to support clinical utility determinations may be obtained from clinical trials. However, clinical laboratories are often not involved in clinical trials, and laboratory specialists may not be experienced in conducting such trials. Many established laboratory tests have never had clinical utility determined. Prospective studies assessing a diagnostic test's impact on clinical outcomes may require long-term patient monitoring, which is problematic. This paper presents methods that may be used to assess clinical utility.

An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles

OBJECTIVE

New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers.

DESIGN

A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles.

RESULTS

Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence.

CONCLUSION

New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact.

Clinical evidence requirements according to the IVDR 2017/746: practical tools and references for underpinning clinical evidence of IVD-MDs

In May 2022, the European Regulation 2017/746 (IVDR) came into force. It changes the approach of in vitro medical devices (IVD-MDs) for industry and institutions. It reinforces the clinical evidence requirements to improve performance, safety and transparency. Despite extended transition periods and existing guides, IVDR remains difficult to interpret and bringing devices into compliance requires efforts. The generation of clinical evidence is essential to demonstrate compliance with IVDR, and encompasses scientific validity, analytical performance and clinical performance. It is required to demonstrate, per intended use in the target population and clinical care pathway, IVD-MDs clinical performance (compared to a predefined clinical performance). Thus, there is a need for IVD-manufacturers and end-users in health care institutions, to obtain guidance on how to generate this clinical evidence. This article aims industrials and clinicians to identify key steps imposed by the IVDR for bringing IVD-MDs to the EU-market. We propose a general view of performance evaluation requirements for IVD-MDs and provide key references, including how to establish study design that will enable to document clinical performance of existing, refined or emerging medical tests. Finally, we propose a roadmap to address the relevant questions and studies in relation to the documents requested in the IVDR.

ISO 15189 is a sufficient instrument to guarantee high-quality manufacture of laboratory developed tests for in-house-use conform requirements of the European In-Vitro-Diagnostics Regulation

The EU In-Vitro Diagnostic Device Regulation (IVDR) aims for transparent risk-and purpose-based validation of diagnostic devices, traceability of results to uniquely identified devices, and post-market surveillance. The IVDR regulates design, manufacture and putting into use of devices, but not medical services using these devices. In the absence of suitable commercial devices, the laboratory can resort to laboratory-developed tests (LDT) for in-house use. Documentary obligations (IVDR Art 5.5), the performance and safety specifications of ANNEX I, and development and manufacture under an ISO 15189-equivalent quality system apply. LDTs serve specific clinical needs, often for low volume niche applications, or correspond to the translational phase of new tests and treatments, often extremely relevant for patient care. As some commercial tests may disappear with the IVDR roll-out, many will require urgent LDT replacement. The workload will also depend on which modifications to commercial tests turns them into an LDT, and on how national legislators and competent authorities (CA) will handle new competences and responsibilities. We discuss appropriate interpretation of ISO 15189 to cover IVDR requirements. Selected cases illustrate LDT implementation covering medical needs with commensurate management of risk emanating from intended use and/or design of devices. Unintended collateral damage of the IVDR comprises loss of non-profitable niche applications, increases of costs and wasted resources, and migration of innovative research to more cost-efficient environments. Taking into account local specifics, the legislative framework should reduce the burden on and associated opportunity costs for the health care system, by making diligent use of existing frameworks.

Electrochemical ELASA: improving early cancer detection and monitoring

The discovery of new molecular biomarkers of cancer during the last decades and the development of new diagnostic devices exploiting those have significantly contributed to the clinical analysis of cancer and to improve the outcomes. Among those, liquid biopsy sensors exploiting aptamers for the detection of cancer biomarkers in body fluids are useful and accurate tools for a fast and inexpensive non-invasive screening of population. The incorporation of aptamers in electrochemical sandwich biosensors using enzyme labels, a so-called ELASA, has demonstrated its utility to improve the detection schemes. In this review, we overview the existing ELASA assays for numerous cancer biomarkers as alternatives to the traditional ELISA and discuss their possibilities to reach the market, currently dominated by optical immunoassays.

From research cohorts to the patient - a role for "omics" in diagnostics and laboratory medicine?

Human pathologies are complex and might benefit from a more holistic diagnostic approach than currently practiced. Omics is a concept in biological research that aims to comprehensively characterize and quantify large numbers of biological molecules in complex samples, e.g., proteins (proteomics), low molecular weight molecules (metabolomics), glycans (glycomics) or amphiphilic molecules (lipidomics). Over the past decades, respective unbiased discovery approaches have been intensively applied to investigate functional physiological and pathophysiological relationships in various research study cohorts. In the context of clinical diagnostics, omics approaches seem to have potential in two main areas: (i) biomarker discovery i.e. identification of individual marker analytes for subsequent translation into diagnostics (as classical target analyses with conventional laboratory techniques), and (ii) the readout of complex, higher-dimensional signatures of diagnostic samples, in particular by means of spectrometric techniques in combination with biomathematical approaches of pattern recognition and artificial intelligence for diagnostic classification. Resulting diagnostic methods could potentially represent a disruptive paradigm shift away from current one-dimensional (i.e., single analyte marker based) laboratory diagnostics. The underlying hypothesis of omics approaches for diagnostics is that complex, multigenic pathologies can be more accurately diagnosed via the readout of "omics-type signatures" than with the current one-dimensional single marker diagnostic procedures. While this is indeed promising, one must realize that the clinical translation of high-dimensional analytical procedures into routine diagnostics brings completely new challenges with respect to long-term reproducibility and analytical standardization, data management, and quality assurance. In this article, the conceivable opportunities and challenges of omics-based laboratory diagnostics are discussed.

Availability and use of rapid diagnostic tests for the management of acute childhood infections in Europe: A cross-sectional survey of paediatricians

BACKGROUND

Point-of-care-tests (POCTs) have been advocated to optimise care in patients with infections but their actual use varies. This study aimed to estimate the variability in the adoption of current POCTs by paediatricians across Europe, and to explore the determinants of variability.

METHODS AND FINDINGS

A cross-sectional survey was conducted of hospital and primary care paediatricians, recruited through professional networks. Questions focused on the availability and use of currently available POCTs. Data were analysed descriptively and using Median Odds Ratio (MOR) to measure variation between countries. Multilevel regression modelling using changes in the area under the receiver operating characteristic curve of models were used to assess the contribution of individual or workplace versus country level factors, to the observed variation. The commonest POCT was urine dipsticks (UD) which were available to >80% of primary care and hospital paediatricians in 68% (13/19) and 79% (23/29) countries, respectively. Availability of all POCTs varied between countries. In primary care, the country (MOR) varied from 1.61 (95%CI: 1.04-2.58) for lactate to 7.28 (95%CI: 3.04-24.35) for UD. In hospitals, the country MOR varied from 1.37 (95%CI:1.04-1.80) for lactate to 11.93 (95%CI:3.35-72.23) for UD. Most paediatricians in primary care (69%, 795/1154) and hospital (81%, 962/1188) would use a diagnostic test in the case scenario of an infant with undifferentiated fever. Multilevel regression modelling showed that the country of work was more important in predicting both the availability and use of POCTs than individual or workplace characteristics.

CONCLUSION

There is substantial variability in the adoption of POCTs for the management of acute infections in children across Europe. To inform future implementation of both existing and innovative tests, further research is needed to understand what drives the variation between countries, the needs of frontline clinicians, and the role of diagnostic tests in the management of acute childhood infections.

Diagnostic accuracy of blood tests of inflammation in paediatric appendicitis: a systematic review and meta-analysis

OBJECTIVE

Possible childhood appendicitis is a common emergency presentation. The exact value of blood tests is debated. This study sought to determine the diagnostic accuracy of four blood tests (white cell count (WCC), neutrophil(count or percentage), C reactive protein (CRP) and/or procalcitonin) for childhood appendicitis.

DESIGN

A systematic review and diagnostic meta-analysis. Data sources included MEDLINE, EMBASE, Central, Web of Science searched from inception-March 2022 with reference searching and authors contacted for missing/unclear data. Eligibility criteria was studies reporting the diagnostic accuracy of the four blood tests compared to the reference standard (histology or follow-up). Risk of bias was assessed (QUADAS-2), pooled sensitivity and specificity were generated for each test and commonly presented cut-offs. To provide insight into clinical impact, we present strategies using a hypothetical cohort.

RESULTS

67 studies were included (34 839 children, 13 342 with appendicitis), all in the hospital setting. The most sensitive tests were WCC (≥10 000 cells/µL, 53 studies sensitivity 0.85 (95% CI 0.80 to 0.89)) and absolute neutrophil count (ANC) (≥7500 cells/µL, five studies sensitivity 0.90 (95% CI 0.85 to 0.94)). Combination of WCC or CRP increased sensitivity further(≥10 000 cells/µL or ≥10 mg/L, individual patient data (IPD) of 6 studies, 0.97 (95% CI 0.93 to 0.99)).Applying results to a hypothetical cohort(1000 children with appendicitis symptoms, of whom 400 have appendicitis) 60 and 40 children would be wrongly discharged based solely on WCC and ANC, respectively, 12 with combination of WCC or CRP.The most specific tests were CRP alone (≥50 mg/L, 38 studies, specificity 0.87 (95% CI 0.80 to 0.91)) or combined with WCC (≥10 000 cells/µL and ≥50 mg/L, IPD of six studies, 0.93 (95% CI 0.91 to 0.95)).

CONCLUSIONS

The best performing single blood tests for ruling-out paediatric appendicitis are WCC or ANC; with accuracy improved combining WCC and CRP. These tests could be used at the point of care in combination with clinical prediction rules. We provide insight into the best cut-offs for clinical application.

PROSPERO REGISTRATION NUMBER

CRD42017080036.

Research on point-of-care tests in outpatient care in Germany: A scoping review and definition of relevant endpoints in evaluation studies

BACKGROUND

The fast turnaround time and user-friendliness of point-of-care tests (POCTs) offer a great potential to improve outpatient health care where clinical decisions have to be made during the physician-patient encounter and time resources are limited. The aim of this scoping review is to describe the extent and nature as well as gaps in German research activities on POCT in outpatient care. In addition, we define research endpoints that should be addressed in the comprehensive evaluation of POCTs targeted for outpatient care.

METHODS

We performed a scoping review with a systematic literature search in Medline (via PubMed), Scopus, Web of Science, Cochrane library and Google Scholar for German publications on POCT with relevance to German outpatient care published from January 2005 to November 2020.

RESULTS

Our literature search identified 2,200 unique records. After literature selection 117 articles were included in this scoping review. Just over half of the articles (67/117, 57.3%) were primary research studies with original data, while one third of all the studies (33.3%) were secondary research articles (e.g., review articles). The remaining articles were clinical recommendations / position papers (7/117, 6.0%) and other types of articles (3.4%). The majority of articles focused on POCT use in infectious diseases (44/117, 37.6%), diabetic syndromes (15.4%), cardiac disease (12.0%) or coagulopathies and thrombosis (10.3%), while the remaining articles did not specify the disease (13.7%) or investigated other diseases (11.1%). Similar to international studies, most primary research studies investigated the diagnostic performance of POCT (e.g., sensitivity, specificity). Evidence beyond diagnostic accuracy remains scarce, such as the impact on therapeutic decisions and practice routines, clinical effectiveness, and user perspectives. In line with this, interventional studies (such as RCTs) on the effectiveness of POCT use in German outpatient care are limited. We define six endpoint domains that should be addressed in the evaluation of POCTs targeted for outpatient care: (i) diagnostic performance, (ii) clinical performance, (iii) time and costs, (iv) impact on clinical routines / processes, (v) perspectives of medical professionals and patients, and (vi) broader aspects.

CONCLUSION

There is considerable research activity on POCTs targeted for use in outpatient care in Germany. Data on their potential benefits beyond diagnostic accuracy is often lacking and should be addressed in future POCT research studies.

Overcoming challenges regarding reference materials and regulations that influence global standardization of medical laboratory testing results

BACKGROUND

Standardized results for laboratory tests are particularly important when their interpretation depends on fixed medical practice guidelines or common reference intervals. The medical laboratory community has developed a roadmap for an infrastructure to achieve standardized test results described in the International Organization for Standardization standard 17511:2020 In vitro diagnostic medical devices - Requirements for establishing metrological traceability of values assigned to calibrators, trueness control materials and human samples. Among the challenges to implementing metrological traceability are the availability of fit-for-purpose matrix-based certified reference materials (CRMs) and requirements for regulatory review that differ among countries. A workshop in December 2021 focused on these two challenges and developed recommendations for improved practices.

DISCUSSION

The participants agreed that prioritization of measurands for standardization should be based on their impact on medical decisions in a clinical pathway. Ensuring that matrix-based CRMs are globally available for more measurands will enable fit-for-purpose calibration hierarchies for more laboratory tests. Regulation of laboratory tests is important to ensure safety and effectiveness for the populations served. Because regulations are country or region specific, manufacturers must submit recalibration changes intended to standardize results for regulatory review to all areas in which a measuring system is marketed.

RECOMMENDATIONS

A standardization initiative requires collaboration and planning among all interested stakeholders. Global collaboration should be further developed for prioritization of measurands for standardization, and for coordinating the production and supply of CRMs worldwide. More uniform regulatory submission requirements are desirable when recalibration is implemented to achieve internationally standardized results.

[The promise of omics in the precision medicine era]

The rise of omics technologies that simultaneously measure thousands of molecules in a complex biological sample represents the core of systems biology. These technologies have profoundly impacted biomarkers and therapeutic targets discovery in the precision medicine era. Systems biology aims to perform a systematic probing of complex interactions in biological systems. Powered by high-throughput omics technologies and high-performance computing, systems biology provides relevant, resolving, and multi-scale overviews from cells to populations. Precision medicine takes advantage of these conceptual and technological developments and is based on two main pillars: the generation of multimodal data and their subsequent modeling. High-throughput omics technologies enable the comprehensive and holistic extraction of biological information, while computational capabilities enable multidimensional modeling and, as a result, offer an intuitive and intelligible visualization. Despite their promise, translating these technologies into clinically actionable tools has been slow. In this contribution, we present the most recent multi-omics data generation and analysis strategies and their clinical deployment in the post-genomic era. Furthermore, medical application challenges of omics-based biomarkers are discussed.

Reference intervals of urinary kidney injury biomarkers for middle-aged men and women determined by quantitative protein mass spectrometry

BACKGROUND AND AIMS

There is an ongoing need to recognize early kidney injury and its progression in structural chronic pathologies. The proteins NGAL, IGFBP7, TIMP2, KIM-1, CXCL9, TGF-β1, SLC22A2, nephrin, cubilin and uromodulin have been proposed as early kidney injury biomarkers. To guide clinical interpretation, their urinary concentrations should be accompanied by reference intervals, which we here establish in a representative Dutch middle-aged population.

MATERIALS AND METHODS

The 24-h urine samples from 1443 Caucasian middle-aged men and women, were analyzed for the biomarkers by quantitative LC-MS/MS. Biomarker excretion per 24-h were calculated, and urine creatinine and osmolality were measured for dilution normalization. This population was characterized by demographic and anthropometric parameters, comorbid conditions, and conventional kidney function measures.

RESULTS

NGAL, IGFBP7, TIMP2, KIM-1 and uromodulin could be quantified in this population, whereas nephrin, SLC22A2 and CXCL9 were below their detection limits. Urine creatinine and osmolality ( r= -were correlated to urine volume (r = -0.71; -0.74) and to IGFBP7 (r = 0.73; 0.71) and TIMP2 (r = 0.71; 0.69). Crude and normalized biomarker concentrations were affected by sex, but not by age, BMI, smoking, kidney function or common comorbid conditions. The reference intervals (men; women) were 18-108; 21-131 pmol IGFBP7/mmol creatinine, 1- 63; 4-224 pmol NGAL/mmol creatinine, 7-48; 7- 59 pmol TIMP2/mmol creatinine, <1-9; <1-12 pmol KIM-1/mmol creatinine and 0.1-1.2; 0.1-1.7 mg uromodulin/mmol creatinine.

CONCLUSION

We present dilution-normalized and sex-stratified urinary reference intervals of kidney injury biomarkers in a middle-aged Caucasian population.

'Diagnostic downshift': clinical and system consequences of extrapolating secondary care testing tactics to primary care

Numerous drivers push specialist diagnostic approaches down to primary care ('diagnostic downshift'), intuitively welcomed by clinicians and patients. However, primary care's different population and processes result in under-recognised, unintended consequences. Testing performs poorer in primary care, with indication creep due to earlier, more undifferentiated presentation and reduced accuracy due to spectrum bias and the 'false-positive paradox'. In low-prevalence settings, tests without near-100% specificity have their useful yield eclipsed by greater incidental or false-positive findings. Ensuing cascades and multiplier effects can generate clinician workload, patient anxiety, further low-value tests, referrals, treatments and a potentially nocebic population 'disease' burden of unclear benefit. Increased diagnostics earlier in pathways can burden patients and stretch general practice (GP) workloads, inducing downstream service utilisation and unintended 'market failure' effects. Evidence is tenuous for reducing secondary care referrals, providing patient reassurance or meaningfully improving clinical outcomes. Subsequently, inflated investment in per capita testing, at a lower level in a healthcare system, may deliver diminishing or even negative economic returns. Test cost poorly represents 'value', neglecting under-recognised downstream consequences, which must be balanced against therapeutic yield. With lower positive predictive values, more tests are required per true diagnosis and cost-effectiveness is rarely robust. With fixed secondary care capacity, novel primary care testing is an added cost pressure, rarely reducing hospital activity. GP testing strategies require real-world evaluation, in primary care populations, of all downstream consequences. Test formularies should be scrutinised in view of the setting of care, with interventions to focus rational testing towards those with higher pretest probabilities, while improving interpretation and communication of results.

Health Technology Assessment to assess value of biomarkers in the decision-making process

Clinical practice guidelines (CPGs) on screening, surveillance, and treatment of several diseases recommend the selective use of biomarkers with central role in clinical decision-making and move towards including patients in this process. To this aim we will clarify the multidisciplinary interactions required to properly measure the cost-effectiveness of biomarkers with regard to the risk-benefit of the patients and how Health Technology Assessment (HTA) approach may assess value of biomarkers integrated within the decision-making process. HTA through the interaction of different skills provides high-quality research information on the effectiveness, costs, and impact of health technologies, including biomarkers. The biostatistical methodology is relevant to HTA but only meta-analysis is covered in depth, whereas proper approaches are needed to estimate the benefit-risk balance ratio. Several biomarkers underwent HTA evaluation and the final reports have pragmatically addressed: 1) a redesign of the screening based on biomarker; 2) a de-implementation/replacement of the test in clinical practice; 3) a selection of biomarkers with potential predictive ability and prognostic value; and 4) a stronger monitoring of the appropriateness of test request. The COVID-19 pandemic has disclosed the need to create a robust and sustainable system to urgently deal with global health concerns and the HTA methodology enables rapid cost-effective implementation of diagnostic tests allowing healthcare providers to make critical patient-management decisions.

Concordance of apolipoprotein B concentration with the Friedewald, Martin-Hopkins, and Sampson formulas for calculating LDL cholesterol

Introduction

Two new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles.

Materials and methods

In a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared.

Results

The Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula.

Conclusion

The Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula.

"It Was Very Comforting to Find Out Right Away." - Patient Perspectives on Point-of-Care Molecular SARS-CoV-2 Testing in Primary Care

BACKGROUND

The use of point-of-care tests (POCTs) has been a central strategy to cope with the COVID-19 pandemic. Yet, evidence on the application and consequences of POCTs within medical settings is rare.

PURPOSE

To assess and understand patient perspectives on molecular point-of-care SARS-CoV-2 testing conducted in primary care.

METHODS

We conducted a cross-sectional survey study among patients who were tested with a molecular SARS-CoV-2 rapid test (ID NOW^TM COVID-19 rapid test, Abbott) in 13 primary care practices in the state of Thuringia (Germany) from February to April 2021. The following aspects were covered in the questionnaire through rating scales and open text formats: test characteristics, trust in test result, consequences of immediate result, cost amount willing to pay and expectations in the future. Open text answers were categorized; quantitative data were analyzed using descriptive statistics and a Mann-Whitney U-test to reveal differences in cost contribution depending on the test result.

RESULTS

A total of 215 patients from nine family practices and one pediatric practice participated. The immediate availability of the test result was important to the majority of patients (94.3%). 95.7% of patients trusted in their test result. Personal consequences of the immediate test result referred to pandemic measures, certainty of action and reassurance. For further tests, patients were willing to pay between 0€ and 100€ (interquartile range = 10-25€) for the molecular SARS-CoV-2 POCT, regardless of the test result. Expectations of being offered the test again in case of renewed cold symptoms were reported by 96.2%.

CONCLUSION

Patients highly appreciated molecular SARS-CoV-2 rapid testing conducted in primary care practices. The immediate availability of the test result led to adjustments in patients' behavior and emotional wellbeing. However, potentially challenging for the implementation of POCTs in primary care practices may be the reimbursement of test costs and patients' expectations in future situation.

Evaluating the prognostic performance of a polygenic risk score for breast cancer risk stratification

BACKGROUND

Polygenic risk scores (PRS) could potentially improve breast cancer screening recommendations. Before a PRS can be considered for implementation, it needs rigorous evaluation, using performance measures that can inform about its future clinical value.

OBJECTIVES

To evaluate the prognostic performance of a regression model with a previously developed, prevalence-based PRS and age as predictors for breast cancer incidence in women from the Estonian biobank (EstBB) cohort; to compare it to the performance of a model including age only.

METHODS

We analyzed data on 30,312 women from the EstBB cohort. They entered the cohort between 2002 and 2011, were between 20 and 89 years, without a history of breast cancer, and with full 5-year follow-up by 2015. We examined PRS and other potential risk factors as possible predictors in Cox regression models for breast cancer incidence. With 10-fold cross-validation we estimated 3- and 5-year breast cancer incidence predicted by age alone and by PRS plus age, fitting models on 90% of the data. Calibration, discrimination, and reclassification were calculated on the left-out folds to express prognostic performance.

RESULTS

A total of 101 (3.33‰) and 185 (6.1‰) incident breast cancers were observed within 3 and 5 years, respectively. For women in a defined screening age of 50-62 years, the ratio of observed vs PRS-age modelled 3-year incidence was 0.86 for women in the 75-85% PRS-group, 1.34 for the 85-95% PRS-group, and 1.41 for the top 5% PRS-group. For 5-year incidence, this was respectively 0.94, 1.15, and 1.08. Yet the number of breast cancer events was relatively low in each PRS-subgroup. For all women, the model's AUC was 0.720 (95% CI: 0.675-0.765) for 3-year and 0.704 (95% CI: 0.670-0.737) for 5-year follow-up, respectively, just 0.022 and 0.023 higher than for the model with age alone. Using a 1% risk prediction threshold, the 3-year NRI for the PRS-age model was 0.09, and 0.05 for 5 years.

CONCLUSION

The model including PRS had modest incremental performance over one based on age only. A larger, independent study is needed to assess whether and how the PRS can meaningfully contribute to age, for developing more efficient screening strategies.

Effect of faecal calprotectin testing on referrals for children with chronic gastrointestinal symptoms in primary care: study protocol for a cluster randomised controlled trial

INTRODUCTION

Children with chronic gastrointestinal symptoms are frequently seen in primary care, yet general practitioners (GPs) often experience challenges distinguishing functional gastrointestinal disorders (FGID) from organic disorders. We, therefore, aim to evaluate whether a test strategy that includes point-of-care testing (POCT) for faecal calprotectin (FCal) can reduce the referral rate to paediatric specialist care among children with chronic gastrointestinal symptoms. The study findings will contribute to improving the recommendations on FCal use among children in primary care.

METHODS AND ANALYSIS

In this pragmatic cluster randomised controlled trial, we will randomise general practices into intervention and control groups. The intervention group will use FCal-POCT when indicated, after completing online training about its indication, interpretation and follow-up as well as communicating an FGID diagnosis. The control group will test and treat according to Dutch GP guidelines, which advise against FCal testing in children. GPs will include children aged 4-18 years presenting to primary care with chronic diarrhoea and/or recurrent abdominal pain. The primary outcome will be the referral rate for children with chronic gastrointestinal symptoms within 6 months after the initial assessment. Secondary outcomes will be evaluated by questionnaires completed at baseline and at 3- and 6-month follow-up. These outcomes will include parental satisfaction and concerns, gastrointestinal symptoms, impact of symptoms on daily function, quality of life, proportion of children with paediatrician-diagnosed FGID referred to secondary care, health service use and healthcare costs. A sample size calculation indicates that we need to recruit 158 GP practices to recruit 406 children.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee (MREC) of the University Medical Center Groningen (The Netherlands) approved this study (MREC number: 201900309). The study results will be made available to patients, GPs, paediatricians and laboratories via peer-reviewed publications and in presentations at (inter)national conferences.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Register: NL7690 (Pre-results).

Unintended consequences: quantifying the benefits, iatrogenic harms and downstream cascade costs of musculoskeletal MRI in UK primary care

OBJECTIVES

The largest proportion of general practitioner (GP) magnetic resonance imaging (MRI) is musculoskeletal (MSK), with consistent annual growth. With limited supporting evidence and potential harms from early imaging overuse, we evaluated practice to improve pathways and patient safety.

METHODS

Cohort evaluation of routinely collected diagnostic and general practice data across a UK metropolitan primary care population. We reviewed patient characteristics, results and healthcare utilisation.

RESULTS

Of 306 MSK-MRIs requested by 107 clinicians across 29 practices, only 4.9% (95% CI ±2.4%) appeared clearly indicated and only 16.0% (95% CI ±4.1%) received appropriate prior therapy. 37.0% (95% CI ±5.5%) documented patient imaging request. Most had chronic symptoms and half had psychosocial flags. Mental health was addressed in only 11.8% (95% CI ±6.3%) of chronic sufferers with psychiatric illness, suggesting a solely pathoanatomical approach to MSK care. Only 7.8% (95% CI ±3.0%) of all patients were appropriately managed without additional referral. 1.3% (95% CI ±1.3%) of scans revealed diagnoses leading to change in treatment (therapeutic yield). Most imaged patients received pathoanatomical explanations to their symptoms, often based on expected age or activity-related changes. Only 16.7% (95% CI ±4.2%) of results appeared correctly interpreted by GPs, with spurious overperception of surgical targets in 65.4% (95% CI ±5.3%) who suffered 'low-value' (ineffective, harmful or wasteful) post-MRI referral cascades due to misdiagnosis and overdiagnosis. Typically, 20%-30% of GP specialist referrals convert to a procedure, whereas MRI-triggered referrals showed near-zero conversion rate. Imaged patients experienced considerable delay to appropriate care. Cascade costs exceeded direct-MRI costs and GP-MSK-MRI potentially more than doubles expenditure compared with physiotherapist-led assessment services, for little-to-no added therapeutic yield, unjustifiable by cost-consequence or cost-utility analysis.

CONCLUSION

Unfettered GP-MSK-MRI use has reached unaccceptable indication creep and disutility. Considerable avoidable harm occurs through ubiquitous misinterpretation and salient low-value referral cascades for two-thirds of imaged patients, for almost no change in treatment. Any marginally earlier procedural intervention for a tiny fraction of patients is eclipsed by negative consequences for the vast majority. Only 1-2 patients need to be scanned for one to suffer mismanagement. Direct-access imaging is neither clinically, nor cost-effective and deimplementation could be considered in this setting. GP-MSK-MRI fuels unnecessary healthcare utilisation, generating nocebic patient beliefs and expectations, whilst appropriate care is delayed and a high burden of psychosocial barriers to recovery appear neglected.

Quantifying atherogenic lipoproteins for lipid-lowering strategies: consensus-based recommendations from EAS and EFLM

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), LDL cholesterol (LDLC), and calculated non-HDLC (=total - HDLC) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDLC is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDLC shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a) [Lp(a)]-cholesterol is part of measured or calculated LDLC and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDLC declines poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDLC or apolipoprotein B (apoB), especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDLC includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apoB measurement can detect elevated LDL particle (LDLP) numbers often unidentified on the basis of LDLC alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.

Health economic evaluations of medical tests: Translating laboratory information into value - A case study example

Health-care providers and funders are focused on identifying value in all their services and that includes laboratories. This means that in order to gain a share of scarce resources, laboratory professionals must also understand and assess the value of tests and that includes their economic impact. This can be assessed using health economic modelling tools which, when used in conjunction with a detailed value proposition for the test, can translate laboratory information into value. While a variety of health economic assessment tools are available, this review will focus on the use of decision analytic models which essentially compare the outcomes from pathways with and without the new test, the value of which is being assessed. A step-by-step framework is provided to guide laboratory professionals through the essential steps of conducting the evaluation. Initial steps include mapping the clinical pathway, understanding the goal of the evaluation, identifying the key stakeholders and their needs and determining a suitable analytical model. Following collection of the actual data, the validity of the model must be checked, and the robustness of the outcomes tested through sensitivity analysis. The last step is to translate the findings into measures of value which can then inform appropriate decisions by the stakeholders. This review of basic health economic modelling should enable laboratory professionals to have an understanding of how modelling can be applied to tests in their own environment and help deliver their potential value.

Role of point-of-care tests in the management of febrile children: a qualitative study of hospital-based doctors and nurses in England

OBJECTIVES

The use of rapid point-of-care tests (POCTs) has been advocated for improving patient management and outcomes and for optimising antibiotic prescribing. However, few studies have explored healthcare workers' views about their use in febrile children. The aim of this study was to explore the perceptions of hospital-based doctors and nurses regarding the use of POCTs in England.

STUDY DESIGN

Qualitative in-depth interviews with purposively selected hospital doctors and nurses. Data were analysed thematically.

SETTING

Two university teaching hospitals in London and Newcastle.

PARTICIPANTS

24 participants (paediatricians, emergency department doctors, trainee paediatricians and nurses).

RESULTS

There were diverse views about the use of POCTs in febrile children. The reported advantages included their ease of use and the rapid availability of results. They were seen to contribute to faster clinical decision-making; the targeting of antibiotic use; improvements in patient care, flow and monitoring; cohorting (ie, the physical clustering of hospitalised patients with the same infection to limit spread) and enhancing communication with parents. These advantages were less evident when the turnaround for results of laboratory tests was 1-2 hours. Factors such as clinical experience and specialty, as well as the availability of guidelines recommending POCT use, were also perceived as influential. However, in addition to their perceived inaccuracy, participants were concerned about POCTs not resolving diagnostic uncertainty or altering clinical management, leading to a commonly expressed preference for relying on clinical skills rather than test results solely.

CONCLUSION

In this study conducted at two university teaching hospitals in England, participants expressed mixed opinions about the utility of current POCTs in the management of febrile children. Understanding the current clinical decision-making process and the specific needs and preferences of clinicians in different settings will be critical in ensuring the optimal design and deployment of current and future tests.

The Time Has Come for Quantitative Protein Mass Spectrometry Tests That Target Unmet Clinical Needs

Protein mass spectrometry (MS) is an enabling technology that is ideally suited for precision diagnostics. In contrast to immunoassays with indirect readouts, MS quantifications are multiplexed and include identification of proteoforms in a direct manner. Although widely used for routine measurements of drugs and metabolites, the number of clinical MS-based protein applications is limited. In this paper, we share our experience and aim to take away the concerns that have kept laboratory medicine from implementing quantitative protein MS. To ensure added value of new medical tests and guarantee accurate test results, five key elements of test evaluation have been established by a working group within the European Federation for Clinical Chemistry and Laboratory Medicine. Moreover, it is emphasized to identify clinical gaps in the contemporary clinical pathways before test development is started. We demonstrate that quantitative protein MS tests that provide an additional layer of clinical information have robust performance and meet long-term desirable analytical performance specifications as exemplified by our own experience. Yet, the adoption of quantitative protein MS tests into medical laboratories is seriously hampered due to its complexity, lack of robotization and high initial investment costs. Successful and widespread implementation in medical laboratories requires uptake and automation of this next generation protein technology by the In-Vitro Diagnostics industry. Also, training curricula of lab workers and lab specialists should include education on enabling technologies for transitioning to precision medicine by quantitative protein MS tests.

Rational selection of a biomarker panel targeting unmet clinical needs in kidney injury

The pipeline of biomarker translation from bench to bedside is challenging and limited biomarkers have been adopted to routine clinical care. Ideally, biomarker research and development should be driven by unmet clinical needs in health care. To guide researchers, clinical chemists and clinicians in their biomarker research, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has developed a structured questionnaire in which the clinical gaps in current clinical pathways are identified and desirable performance specifications are predefined. In kidney injury, the high prevalence of the syndrome acute kidney injury (AKI) in the hospital setting has a significant impact on morbidity, patient survival and health care costs, but the use of biomarkers indicating early kidney injury in daily patient care remains limited. Routinely, medical labs measure serum creatinine, which is a functional biomarker, insensitive for detecting early kidney damage and cannot distinguish between renal and prerenal AKI. The perceived unmet clinical needs in kidney injury were identified through the EFLM questionnaire. Nephrologists within our tertiary care hospital emphasized that biomarkers are needed for (1) early diagnosis of in-hospital AKI after a medical insult and in critically ill patients, (2) risk stratification for kidney injury prior to a scheduled (elective) intervention, (3) kidney injury monitoring in patients scheduled to receive nephrotoxic medication and after kidney transplantation and (4) differentiation between prerenal AKI and structural kidney damage. The biomarker search and selection strategy resulted in a rational selection of an eleven-protein urinary panel for kidney injury that target these clinical needs. To assess the clinical utility of the proposed biomarker panel in kidney injury, a multiplexed LC-MS test is now in development for the intended translational research.

Setting minimum clinical performance specifications for tests based on disease prevalence and minimum acceptable positive and negative predictive values: Practical considerations applied to COVID-19 testing

OBJECTIVES

Several guidelines for the evaluation of laboratory tests for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection have recommended establishing an a priori definition of minimum clinical performance specifications before test selection and method evaluation.

METHODS

Using positive (PPV) and negative predictive values (NPV), we constructed a spreadsheet tool for determining the minimum clinical specificity (conditional on NPV or PPV, sensitivity and prevalence) and minimum clinical sensitivity (conditional on NPV or PPV, specificity and prevalence) of tests.

RESULTS

At a prevalence of 1%, there are no minimum sensitivity requirements to achieve a desired NPV of 60%-95% for a given clinical specificity above 20%. It is not possible to achieve 60-95% PPV even with 100% clinical sensitivity, except when the clinical specificity is near 100%. The opposite trend is seen in high prevalence settings (60%), where a relatively low minimum clinical sensitivity is required to achieve a desired PPV for a given clinical specificity, and a higher minimum clinical specificity is required to achieve a desired NPV for a given clinical sensitivity.

DISCUSSION

The selection of laboratory tests and the testing strategy for SARS-CoV-2 involves delicate trade-offs between NPV and PPV based on prevalence and clinical sensitivity and clinical specificity. Practitioners and health authorities should carefully consider the clinical scenarios under which the test result will be used and select the most appropriate testing strategy that fulfils the a priori defined clinical performance specification.

Biological variation: Understanding why it is so important?

This Review will describe the increasing importance of the concepts of biological variation to clinical chemists. The idea of comparison to 'reference' is fundamental in measurement. For the biological measurands, that reference is the relevant patient population, a clinical decision point based on a trial or an individual patient's previous results. The idea of using biological variation to set quality goals was then realised for setting Quality Control (QC) and External Quality Assurance (EQA) limits. The current phase of BV integration into practice is using Patient-Based Real-Time Quality Control (PBRTQC) and Patient Based Quality Assurance (PBQA) to detect a change in assay performance. The challenge of personalised medicine is to determine an individual reference interval. The Athletes Biological Passport may provide the solution.

We need to talk about the analytical performance of our laboratory developed clinical LC-MS/MS tests, and start separating the wheat from the chaff

With the upcoming EU regulation on the use of in-vitro diagnostic devices, a critical evaluation of the current status of our in-house developed LC-MS/MS methods is timely and of great relevance. Recently, much attention has been devoted to the need for better specification of analytical and clinical performance. Appropriate reporting of the actual achieved analytical performance is an important determinant of the clinical performance and subsequent clinical effectiveness of a test. We advocate for the application of CLSI C62-A guidelines for method validation and suggest some adaptations for analytical validation of in-house developed LC-MS/MS methods for endogenous substances. Additionally, we underline the importance of well-equipped reviewers and standardized method description, including the presentation of figural evidence of obtained method performance. Achieving this ensures future quality of our in-house developed LC-MS/MS methods.

Mass spectrometry in clinical glycomics: The path from biomarker identification to clinical implementation

Over the past decades, the genome and proteome have been widely explored for biomarker discovery and personalized medicine. However, there is still a large need for improved diagnostics and stratification strategies for a wide range of diseases. Post-translational modification of proteins by glycosylation affects protein structure and function, and glycosylation has been implicated in many prevalent human diseases. Numerous proteins for which the plasma levels are nowadays evaluated in clinical practice are glycoproteins. While the glycosylation of these proteins often changes with disease, their glycosylation status is largely ignored in the clinical setting. Hence, the implementation of glycomic markers in the clinic is still in its infancy. This is for a large part caused by the high complexity of protein glycosylation itself and of the analytical techniques required for their robust quantification. Mass spectrometry-based workflows are particularly suitable for the quantification of glycans and glycoproteins, but still require advances for their transformation from a biomedical research setting to a clinical laboratory. In this review, we describe why and how glycomics is expected to find its role in clinical tests and the status of current mass spectrometry-based methods for clinical glycomics.

Analytical assessment of ortho clinical diagnostics high-sensitivity cardiac troponin I assay

Objectives

To analytically evaluate Ortho Clinical Diagnostics VITROS high-sensitivity cardiac troponin I (hs-cTnI) assay in specific matrices with comparison to other hs-cTn assays.

Methods

The limit of detection (LoD), imprecision, interference and stability testing for both serum and lithium heparin (Li-Hep) plasma for the VITROS hs-cTnI assay was determined. We performed Passing-Bablok regression analyses between sample types for the VITROS hs-cTnI assay and compared them to the Abbott ARCHITECT, Beckman Access and the Siemens ADVIA Centaur hs-cTnI assays. We also performed Receiver-operating characteristic curve analyses with the area under the curve (AUC) determined in an emergency department (ED)-study population (n=131) for myocardial infarction (MI).

Results

The VITROS hs-cTnI LoD was 0.73 ng/L (serum) and 1.4 ng/L (Li-Hep). Stability up to five freeze-thaws was observed for the Ortho hs-cTnI assay, with the analyte stability at room temperature in serum superior to Li-Hep with gross hemolysis also affecting Li-Hep plasma hs-cTnI results. Comparison of Li-Hep to serum concentrations (n=202), yielded proportionally lower concentrations in plasma with the VITROS hs-cTnI assay (slope=0.85; 95% confidence interval [CI]:0.83-0.88). In serum, the VITROS hs-cTnI concentrations were proportionally lower compared to other hs-cTnI assays, with similar slopes observed between assays in samples frozen <-70 °C for 17 years (ED-study) or in 2020. In the ED-study, the VITROS hs-cTnI assay had an AUC of 0.974 (95%CI:0.929-0.994) for MI, similar to the AUCs of other hs-cTn assays.

Conclusions

Lack of standardization of hs-cTnI assays across manufacturers is evident. The VITROS hs-cTnI assay yields lower concentrations compared to other hs-cTnI assays. Important differences exist between Li-Hep plasma and serum, with evidence of stability and excellent clinical performance comparable to other hs-cTn assays.

Testing COVID-19 tests faces methodological challenges

In battling the COVID-19 pandemic, testing is essential. The detection of viral RNA allows the identification of infected persons, whereas the detection of antibodies may reveal a response to a previous infection. Tests for coronavirus should be rigorously evaluated in terms of their analytical and clinical performance. This poses not only logistic challenges, but also methodological ones. Some of these are generic for the diagnostic accuracy paradigm, whereas others are more specific for tests for viruses. Problematic for evaluations of the clinical performance of tests for viral RNA is the absence of an independent reference standard. Many studies lack rigor in terms of the recruitment of study participants. Study reports are often insufficiently informative, which makes it difficult to assess the applicability of study findings. Attempts to summarize the performance of these tests in terms of a single estimate of the clinical sensitivity fail to do justice to the identifiable sources of the large heterogeneity in mechanisms for generating false negative results.

Bringing Greater Accuracy to Europe's Healthcare Systems: The Unexploited Potential of Biomarker Testing in Oncology

Rapid and continuing advances in biomarker testing are not being matched by take-up in health systems, and this is hampering both patient care and innovation. It also risks costing health systems the opportunity to make their services more efficient and, over time, more economical. This paper sets out the potential of biomarker testing, the unfolding precision and range of possible diagnosis and prediction, and the many obstacles to adoption. It offers case studies of biomarker testing in breast, ovarian, prostate, lung, thyroid and colon cancers, and derives specific lessons as to the potential and actual use of each of them. It also draws lessons about how to improve access and alignment, and to remedy the data deficiencies that impede development. And it suggests solutions to outstanding issues - notably including funding and the tangled web of obtaining reimbursement or equivalent coverage that Europe's fragmented health system implies. It urges a European evolution towards an initial minimum testing scenario, which would guarantee universal access to a suite of biomarker tests for the currently most common conditions, and, further into the future, to an optimum testing scenario in which a much wider range of biomarker tests would be introduced and become part of a more sophisticated health system articulated around personalised medicine. For exploiting genomics to the full, it argues the need for a new policy framework for Europe. Biomarker testing is not an issue that can be treated in isolation, since the purpose of testing is to improve health. Its use is therefore always closely linked to specific health challenges and needs to be viewed in the broader policy context in the EU and more widely. The paper is the result of extensive engagement with experts and decision makers to develop the framework, and consequently represents a wide consensus of views on how healthcare systems should respond from push and pull factors at local, national and cross-border and EU level. It contains strong views and clear recommendations springing from the convictions of patients, clinicians, academics, medicines authorities, HTA bodies, payers, the diagnostic, pharmaceutical and ICT industries, and national policy makers.

Who Conducts Health Economic Evaluations of Laboratory Tests? A Scoping Review

Background

Health economic evaluations (HEEs) are effectively used to inform decision making in healthcare. We sought to assess the level of involvement of laboratory professionals (LPs) in HEEs of laboratory tests.

Methods

A systematic literature search was conducted in Medline (2013 to November 28, 2018) for original articles reporting HEEs of medical laboratory tests. Eligible studies were characterized by indication, utilization, region, setting, study design, primary outcome measures, and sponsorship. Authors were classified based on stated affiliation as clinician, scientist, public health expert, or LP.

Results

In total, 140 HEEs were included in the study, of which 24 (17.1%) had contributions from LPs. Studies were primarily focused on infectious disease (n = 68), oncology (n = 23), and cardiovascular disease (n = 16). Cost-utility or cost-effectiveness analyses (n = 117) were the most frequent study types, with effectiveness measured mainly in terms of quality-adjusted life-years (n = 57) and detected cases (n = 41). Overall, 76% of HEEs followed a social or health system perspective, whereas 15% took a hospital viewpoint. Partial or full funding was received from public health organizations or industry in 39% and 16% of studies, respectively. The involvement of LPs was associated with test utilization, secondary care, analytic perspective, and an immediate time horizon (all P &lt; 0.05). Quality of studies was found to be lower in HEEs coauthored by LPs.

Conclusion

Multidisciplinary collaboration is essential to understanding the complexity of clinical pathways. HEEs are used effectively to inform healthcare decision making. The involvement of LPs in HEEs is low. This implies that laboratory expertise is frequently not considered in decision processes.