Approaches to the implementation of the quality system in accordance with ISO 15189:2015 in the Laboratory of Clinical Diagnostics of the Clinical and Diagnostic Center at the National University of Pharmacy on the example of methods for determining the l

Abstract

A modern clinical and diagnostic laboratory should solve the problems of implementing and maintaining the quality system based on the application of the principles of the specialized standard ISO 15189: 2015 “Medical laboratories. Some requirements for quality and competence” as an element of providing the procedure for assessing the conformity of the laboratory research results. The effective solution of these issues becomes one of the important conditions for accreditation, and the introduction of the assessment of the suitability of methods in daily activities is evidence of the competence of modern clinical and diagnostic laboratories.

Aim. To study the approaches to quality assurance in the Clinical Diagnostics Laboratory of the Clinical Diagnostic Center at the NUPh by carrying out validation procedures for assessing the suitability of biochemical methods for determining levels of lactate dehydrogenase (LDH) and glucose in biological fluids.

Materials and methods. The objects of the study were standardized biochemical methods for determining levels of LDH and glucose. “Chemical control. Reagent kit. Level1” produced by High Technology, Inc. (USA) with the known concentration of analytes was selected as a control serum. The measurements were performed on an Express Express Plus automatic biochemical analyzer manufactured by Bayer Corporation,Germany. When processing the research results the indicators of descriptive statistics were used, and a number of statistical evaluations were carried out.

Results. The procedure for validation of methods consisted of several stages. Protocols and validation reports were developed at the premises of the Clinical Diagnostics Laboratory of theClinicalDiagnosticCenter at the NUPh to assess the suitability of methods for determining LDH and glucose in biological fluids by the photometric method using an Еxpress Рlus biochemical analyzer. Validation was performed using reagents manufactured by High Technology, Inc. (USA) and control materials (standard samples). The following validation characteristics of the methods were determined: specificity, convergence and reproducibility, accuracy, measurement uncertainty. Assessment of the internal laboratory convergence and reproducibility of methods for determining the concentration of LDH and glucose during the operation of the analyzer, which was carried out by two laboratory operators of the same qualification, indicated the absence of gross errors in the operation of the analyzer and statistically important differences in the measurements. Assessment of the correctness of the methods performed using the control serum proved that the systematic error was not significant (according to the given acceptance criterion). Thus, these methods provided correct measurements within the laboratory. The calculation of the expanded uncertainty showed that the values of LDH and glucose levels obtained could be considered accurate and reliable.

Conclusions. Validation of methods for determining lactate dehydrogenase and glucose in the human blood by the photometric method has proven that these methods have performance characteristics that meet the regulated and established criteria, and the parameters measured with their help correspond to the proper ones.