Christoph Ebert

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

Regulators and healthcare payers are increasingly demanding evidence that biomarkers deliver patient benefits to justify their use in clinical practice. Laboratory professionals need to be familiar with these evidence requirements to better engage in biomarker research and decisions about their appropriate use. This paper by a multidisciplinary group of the European Federation of Clinical Chemistry and Laboratory Medicine describes the pathway of a laboratory assay measuring a biomarker to becoming a medically useful test. We define the key terms, principles and components of the test evaluation process. Unlike previously described linearly staged models, we illustrate how the essential components of analytical and clinical performances, clinical and cost-effectiveness and the broader impact of testing assemble in a dynamic cycle. We highlight the importance of defining clinical goals and how the intended application of the biomarker in the clinical pathway should drive each component of test evaluation. This approach emphasizes the interaction of the different components, and that clinical effectiveness data should be fed back to refine analytical and clinical performances to achieve improved outcomes. The framework aims to support the understanding of key stakeholders. The laboratory profession needs to strengthen collaboration with industry and experts in evidence-based medicine, regulatory bodies and policy makers for better decisions about the use of new and existing medical tests.

Current Evidence and Future Perspectives on the Effective Practice of Patient-Centered Laboratory Medicine

BACKGROUND Systematic evidence of the contribution made by laboratory medicine to patient outcomes and the overall process of healthcare is difficult to find. An understanding of the value of laboratory medicine, how it can be determined, and the various factors that influence it is vital to ensuring that the service is provided and used optimally. CONTENT This review summarizes existing evidence supporting the impact of laboratory medicine in healthcare and indicates the gaps in our understanding. It also identifies deficiencies in current utilization, suggests potential solutions, and offers a vision of a future in which laboratory medicine is used optimally to support patient care. SUMMARY To maximize the value of laboratory medicine, work is required in 5 areas: (a) improved utilization of existing and new tests; (b) definition of new roles for laboratory professionals that are focused on optimizing patient outcomes by adding value at all points of the diagnostic brain-to-brain cycle; (c) development of standardized protocols for prospective patient-centered studies of biomarker clinical effectiveness or extraanalytical process effectiveness; (d) benchmarking of existing and new tests in specified situations with commonly accepted measures of effectiveness; (e) agreed definition and validation of effectiveness measures and use of checklists for articles submitted for publication. Progress in these areas is essential if we are to demonstrate and enhance the value of laboratory medicine and prevent valuable information being lost in meaningless data. This requires effective collaboration with clinicians, and a determination to accept patient outcome and patient experience as the primary measure of laboratory effectiveness.

Multicentre performance evaluation of the E170 Module for MODULAR ANALYTICS

Abstract The E170 module was evaluated at 13 sites in an international multicentre study. The objective of the study was to assess the analytical performance of 49 analytes, and to collect feedback on the system’s reliability and practicability. The typical, within-run coefficients of variation (CVs) for most of the quantitative assays ranged between 1 and 2% while a range of 2–4% was achieved with the infectious disease methods. Total precision CVs were found to be within the manufacturer’s expected performance ranges, demonstrating good concordance of the system’s measuring channels and a high reproducibility during the 2–4-week trial period. The functional sensitivity of 11 selected assays met the clinical requirements (e.g., thyreotroponin (TSH) 0.008 mU/l, troponin T 0.02 µg/l, total prostate-specific antigen (PSA) 0.03 µg/l). The E170 showed no drift during an 8-hour period and no relevant reagent carryover. Accuracy was confirmed by ring trial experiments and method comparisons vs. Elecsys® 2010. The reliability and practicability of the system’s hardware and software met with, or even exceeded, the evaluator’s requirements. Workflow studies showed that E170 can cover the combined workload of various routine analysers in a variety of laboratory environment. Throughput and sample processing time requirements were achieved while personnel ‘hands-on-time’ could be reduced.

Setting analytical performance specifications based on outcome studies – is it possible?

Abstract The 1st Strategic Conference of the European Federation of Clinical Chemistry and Laboratory Medicine proposed a simplified hierarchy for setting analytical performance specifications (APS). The top two levels of the 1999 Stockholm hierarchy, i.e., evaluation of the effect of analytical performance on clinical outcomes and clinical decisions have been proposed to be replaced by one outcome-based model. This model can be supported by: (1a) direct outcome studies; and (1b) indirect outcome studies investigating the impact of analytical performance of the test on clinical classifications or decisions and thereby on the probability of patient relevant clinical outcomes. This paper reviews the need for outcome-based specifications, the most relevant types of outcomes to be considered, and the challenges and limitations faced when setting outcome-based APS. The methods of Model 1a and b are discussed and examples are provided for how outcome data can be translated to APS using the linked evidence and simulation or decision analytic techniques. Outcome-based APS should primarily reflect the clinical needs of patients; should be tailored to the purpose, role and significance of the test in a well defined clinical pathway; and should be defined at a level that achieves net health benefit for patients at reasonable costs. Whilst it is acknowledged that direct evaluations are difficult and may not be possible for all measurands, all other forms of setting APS should be weighed against that standard, and regarded as approximations. Better definition of the relationship between the analytical performance of tests and health outcomes can be used to set analytical performance criteria that aim to improve the clinical and cost-effectiveness of laboratory tests.

Biomarker development targeting unmet clinical needs

BACKGROUND The introduction of new biomarkers can lead to inappropriate utilization of tests if they do not fill in existing gaps in clinical care. We aimed to define a strategy and checklist for identifying unmet needs for biomarkers. METHODS A multidisciplinary working group used a 4-step process: 1/ scoping literature review; 2/ face-to-face meetings to discuss scope, strategy and checklist items; 3/ iterative process of feedback and consensus to develop the checklist; 4/ testing and refinement of checklist items using case scenarios. RESULTS We used clinical pathway mapping to identify clinical management decisions linking biomarker testing to health outcomes and developed a 14-item checklist organized into 4 domains: 1/ identifying and 2/ verifying the unmet need; 3/ validating the intended use; and 4/ assessing the feasibility of the new biomarker to influence clinical practice and health outcome. We present an outcome-focused approach that can be used by multiple stakeholders for any medical test, irrespective of the purpose and role of testing. CONCLUSIONS The checklist intends to achieve more efficient biomarker development and translation into practice. We propose the checklist is field tested by stakeholders, and advocate the role of the clinical laboratory professional to foster trans-sector collaboration in this regard.