Analytical performance specifications and quality assurance of point-of-care testing in primary healthcare.

Point-of-care testing (POCT) is the fastest-growing segment of laboratory medicine. This review focuses on the essential aspects of setting analytical performance specifications (APS) and performing quality assurance for POCT in primary healthcare. In-vitro diagnostic medical devices for POCT are typically small and easy to operate.

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.

Harmonising EQA schemes the next frontier: challenging the status quo.

There is a focus on standardisation and harmonisation of laboratory results to reduce the risk of misinterpretation of patient results assayed in different laboratories. External quality assessment (EQA) is critical to assess the need for harmonisation and to monitor the success of procedures to achieve harmonisation. However, EQA providers are being stretched to meet the needs of their participants with proven commutable material with reference method targets, a range of clinically significant levels of the materials, detailed and customised data analysis, and educational support.