How to assess the quality of your analytical method?

Abstract

Laboratory medicine is amongst the fastest growing fields in medicine, crucial in diagnosis, support of prevention and in the monitoring of disease for individual patients and for the evaluation of treatment for populations of patients. Therefore, high quality and safety in laboratory testing has a prominent role in high-quality healthcare. Applied knowledge and competencies of professionals in laboratory medicine increases the clinical value of laboratory results by decreasing laboratory errors, increasing appropriate utilization of tests, and increasing cost effectiveness. This collective paper provides insights into how to validate the laboratory assays and assess the quality of methods. It is a synopsis of the lectures at the 15th European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Continuing Postgraduate Course in Clinical Chemistry and Laboratory Medicine entitled "How to assess the quality of your method?" (Zagreb, Croatia, 24-25 October 2015). The leading topics to be discussed include who, what and when to do in validation/verification of methods, verification of imprecision and bias, verification of reference intervals, verification of qualitative test procedures, verification of blood collection systems, comparability of results among methods and analytical systems, limit of detection, limit of quantification and limit of decision, how to assess the measurement uncertainty, the optimal use of Internal Quality Control and External Quality Assessment data, Six Sigma metrics, performance specifications, as well as biological variation. This article, which continues the annual tradition of collective papers from the EFLM continuing postgraduate courses in clinical chemistry and laboratory medicine, aims to provide further contributions by discussing the quality of laboratory methods and measurements and, at the same time, to offer continuing professional development to the attendees.

Verification and quality control of routine hematology analyzers

“…The fourth column represents the ‘Ricos criteria’ that illustrate biological variation , and these performance criteria are based on biological variability. There is controversy regarding the use of these criteria for method verification ; therefore, we suggest to use the current state‐of‐the‐art CV (%) (columns 2 and 3) as criteria for acceptability of the HA under verification.…”

Quality specifications of routine clinical chemistry methods based on sigma metrics in performance evaluation

“…In many Chinese clinical laboratories, the Westgard multiplication rules (1 3s , 2 2s , R 4s , 4 1s , 10 x ) have been widely used in clinical chemistry. In this method, there may be more false rejection, waste of quality control materials and prolonged test awaiting time (TAT), whereas the sigma metrics approach allows a laboratory to take a broader view of the data, joining estimates of bias and imprecision into a practical judgment on the clinical usefulness of the method's quality control criteria . Thus, it is useful and simple to access and choose optimal internal quality control criteria based on sigma metrics.…”

Establishing reference values and evaluation of an in-house ferric reducing antioxidant power (FRAP) colorimetric assay in microplates

“…Method verification studies were performed to determine if the assay fulfilled the specified requirements [12].…”

“…LoB was estimated by measuring replicates of a blank sample and calculating the mean result and the standard deviation (SD). LoB=mean blank +1.645(SD blank) [12,13].…”