Performance specifications for sodium should not be based on biological variation.

When increasing the quality in clinical laboratories by decreasing measurement uncertainty, reliable methods are needed not only to quantify the performance of measuring systems, but also to set goals for the performance. Sigma metrics used in medical laboratories for documenting and expressing levels of performance, are evidently totally dependent on the "total permissible error" used in the formulas. Although the conventional biological variation (BV) based model for calculation of the permissible (or allowable) total error is commonly used, it has been shown to be flawed.

Measurement uncertainty for practical use.

Uncertainty is an inseparable part of all kinds of measurements performed in clinical laboratories. Accreditation standards including the ISO/IEC 17025:2017 and ISO 15189:2012 require that laboratories have routines for calculating the measurement uncertainty of reported results. Various guidelines such as CLSI EP29, Nordest 537, and ISO 20914:2019 have proposed methods for this purpose.

Awareness of drug laboratory test interactions is important for prevention of unnecessary additional diagnostics: An example.

Background: Elevated levels of Chromogranin A (CgA) may be indicative of a neuroendocrine tumour (NET), but increased levels are also observed after intake of proton pump inhibitors (PPIs). The incidence of diagnostic confusion because of this drug-laboratory test interaction (DLTI) was examined.

Methods: Medical records of 238 patients with elevated CgA concentrations were obtained from three hospitals.

Real-time monitoring of drug laboratory test interactions: a proof of concept.

Objectives: For the correct interpretation of test results, it is important to be aware of drug-laboratory test interactions (DLTIs). If DLTIs are not taken into account by clinicians, erroneous interpretation of test results may lead to a delayed or incorrect diagnosis, unnecessary diagnostic testing or therapy with possible harm for patients. A DLTI alert accompanying a laboratory test result could be a solution.

The end of the laboratory developed test as we know it? Recommendations from a national multidisciplinary taskforce of laboratory specialists on the interpretation of the IVDR and its complications.

The in vitro diagnostic medical devices regulation (IVDR) will take effect in May 2022. This regulation has a large impact on both the manufacturers of in vitro diagnostic medical devices (IVD) and clinical laboratories. For clinical laboratories, the IVDR poses restrictions on the use of laboratory developed tests (LDTs).

Reflective testing - A randomized controlled trial in primary care patients.

Background: Reflective testing, i.e. interpreting, commenting on and, if necessary, adding tests in order to aid the diagnostic process in a meaningful and efficient manner, is an extra service provided by laboratory medicine.

Statistical distributions commonly used in measurement uncertainty in laboratory medicine.

Uncertainty is an inseparable part of all types of measurement. Recently, the International Organization for Standardization (ISO) released a new standard (ISO 20914) on how to calculate measurement uncertainty (MU) in laboratory medicine. This standard can be regarded as the beginning of a new era in laboratory medicine.

Diagnostic error as a result of drug-laboratory test interactions.

Background Knowledge of possible drug-laboratory test interactions (DLTIs) is important for the interpretation of laboratory test results. Test results may be affected by physiological or analytical drug effects. Failure to recognize these interactions may lead to misinterpretation of test results, a delayed or erroneous diagnosis or unnecessary extra tests or therapy, which may harm patients.

Impact of interactions between drugs and laboratory test results on diagnostic test interpretation - a systematic review.

Intake of drugs may influence the interpretation of laboratory test results. Knowledge and correct interpretation of possible drug-laboratory test interactions (DLTIs) is important for physicians, pharmacists and laboratory specialists. Laboratory results may be affected by analytical or physiological effects of medication.

Sigma metrics in laboratory medicine revisited: We are on the right road with the wrong map.

Reliable procedures are needed to quantify the performance of instruments and methods in order to increase the quality in clinical laboratories. The Sigma metrics serves that purpose, and in the present study, the current methods for the calculation of the Sigma metrics are critically evaluated. Although the conventional model based on permissible (or allowable) total error is widely used, it has been shown to be flawed.

Performance specifications and six sigma theory: Clinical chemistry and industry compared.

Analytical performance specifications are crucial in test development and quality control. Although consensus has been reached on the use of biological variation to derive these specifications, no consensus has been reached which model should be preferred. The Six Sigma concept is widely applied in industry for quality specifications of products and can well be compared with Six Sigma models in clinical chemistry.

The use of error and uncertainty methods in the medical laboratory.

Error methods - compared with uncertainty methods - offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine. However, uncertainty methods are preferred in other fields of science as reflected by the guide to the expression of uncertainty in measurement. When laboratory results are used for supporting medical diagnoses, the total uncertainty consists only partially of analytical variation.

A survey of patients' views from eight European countries of interpretive support from Specialists in Laboratory Medicine.

Background: There is increasing interest in direct patient engagement including receiving their laboratory medicine results. We previously established an appetite for Specialists in Laboratory Medicine to support patients in understanding results. The aim of this study was to establish whether patients agreed with such an approach, determined through surveying views in eight European countries.

Could accreditation bodies facilitate the implementation of medical guidelines in laboratories?

Several studies have shown that recommendations related to how laboratory testing should be performed and results interpreted are limited in medical guidelines and that the uptake and implementation of the recommendations that are available need improvement. The EFLM/UEMS Working Group on Guidelines conducted a survey amongst the national societies for clinical chemistry in Europe regarding development of laboratory-related guidelines. The results showed that most countries have guidelines that are specifically related to laboratory testing; however, not all countries have a formal procedure for accepting such guidelines and few countries have guideline committees.

Why are clinical practice guidelines not followed?

Clinical practice guidelines (CPG) are written with the aim of collating the most up to date information into a single document that will aid clinicians in providing the best practice for their patients. There is evidence to suggest that those clinicians who adhere to CPG deliver better outcomes for their patients. Why, therefore, are clinicians so poor at adhering to CPG? The main barriers include awareness, familiarity and agreement with the contents.

Total error vs. measurement uncertainty: revolution or evolution?

The first strategic EFLM conference "Defining analytical performance goals, 15 years after the Stockholm Conference" was held in the autumn of 2014 in Milan. It maintained the Stockholm 1999 hierarchy of performance goals but rearranged them and established five task and finish groups to work on topics related to analytical performance goals including one on the "total error" theory. Jim Westgard recently wrote a comprehensive overview of performance goals and of the total error theory critical of the results and intentions of the Milan 2014 conference.

European views on patients directly obtaining their laboratory test results.

Background: Medicine is a highly professionalized endeavour, by tradition centred on the authority of physicians. Better education and the advent of the information age cater for increased demands on society in general and on health care in particular to enable people to make informed decisions regarding themselves. Participation in medical decisions requires informed knowledge which is hard to obtain without substantial and time consuming professional help.

Proposal for the modification of the conventional model for establishing performance specifications.

Appropriate quality of test results is fundamental to the work of the medical laboratory. How to define the level of quality needed is a question that has been subject to much debate. Quality specifications have been defined based on criteria derived from the clinical applicability, validity of reference limits and reference change values, state-of-the-art performance, and other criteria, depending on the clinical application or technical characteristics of the measurement.

The quality of laboratory aspects of troponin testing in clinical practice guidelines and consensus documents needs to be improved.

Objective: The European Federation of Laboratory Medicine (EFLM) and the Union of European Medical Specialists (UEMS) joint Working Group on guidelines recently proposed a checklist to help standardize the description of laboratory investigations in clinical practice guidelines (CPG).

Methods: Nine CPGs or consensus documents published from 2011 to 2013 describing the investigation of chest pain, diagnosis of acute coronary syndrome, or myocardial infarction were evaluated against the published checklist.

Results: Clinical use of troponin analysis are commonly dealt with but the publications present variable, vague and sometimes conflicting information regarding this laboratory test being very much relied on upon making a diagnosis of acute coronary syndrome.

Laboratory medicine in the European Union.

The profession of laboratory medicine differs between countries within the European Union (EU) in many respects. The objective of professional organizations of the promotion of mutual recognition of specialists within the EU is closely related to the free movement of people. This policy translates to equivalence of standards and harmonization of the training curriculum.