scholarly journals Evaluation of the clinical chemistry tests analytical performance with Sigma Metric by using different quality specifications - Comparison of analyser actual performance with manufacturer data

2021 ◽  
Vol 32 (1) ◽  
Author(s):  
Murat Keleş
2019 ◽  
Vol 45 (1) ◽  
pp. 11-18
Author(s):  
Murat Keleş

Abstract Background The importance of managing analytical quality in clinical laboratories is known. Goal-setting models are critical for analytical quality management, along with correctly implemented error models. However, the methods used to determine analytical performance and more importantly, the relevant analytical quality goals are open to discussion. Our aim was to compare the analytical performance characteristics of routine clinical chemistry tests with different goal-setting models which was proposed by various establishments. In addition, to provide a perspective to Turkish total analytical error (TAE) circular letter that compulsory to calculate from 2016. Materials and methods This study was performed by the data obtained from the internal and external quality control of clinical chemistry tests which were measured by Roche Cobas c501 biochemistry analyzer. TAE calculated with TAE% = 1.65 ×(CV%) + Bias% formula. Nordtest uncertainty model was used in the calculation of measurement uncertainty (MU). In this context, total analytical error was evaluated with biological variation (BV), RCPA, CLIA and Turkish allowable total error (ATE) goals. Measurement uncertainty was evaluated with only permissible measurement uncertainty (pU%) goal. Results In our study, RCPA goals are the most stringent, followed by the BVEuBIVAS, BVRicos, pU%, CLIA and finally the ATETurkey goals coming in last. In cumulatively, BVEuBIVAS goals were 18.3% lower than BVRicos for evaluated parameters. Conclusion The balance between applicability and analytical assurance of goals should be well ensured when determining goal-setting models. Circular letter (2016/18) creates awareness to the analytical quality management but still open to development. Biological variation dependent total allowable error model never designed to be used as benchmarks for measurement uncertainty and it is not methodologically appropriate for assessing measurement uncertainty which was estimated by the Nordtest method. Also considered that, the use of “permissible MU” is more methodologically appropriate in the evaluation of measurement uncertainty.


2017 ◽  
Vol 43 (1) ◽  
pp. 9-14
Author(s):  
Giray Bozkaya ◽  
Murat Aksit ◽  
Merve Zeytinli Aksit

AbstractAim:Emergency department laboratories, besides from giving accurate results, should be quick enough in order not to delay patient care. Giving fast results doesn’t mean to ignore quality, rather it should always be improved to prevent erroneous results. Six sigma is a modern assessment of quality which is used to determine the analytical performance. Our aim was to evaluate the analytical performance of clinical chemistry tests in our emergency department laboratory by using sigma metrics.Materials and methods:Our study was performed by using the internal and external quality assessment data of 13 clinical chemistry tests of emergency laboratory. Sigma levels were calculated using bias, coefficient of variation and total allowable error (TEa) ratios of CLIA, Ricos, Rilibak and Turkey.Results:Sigma levels of various tests (CK, amylase, ALT, AST, urea, creatinine, total bilirubin, sodium and chloride) were found to be ≥6 according to different TEa’s, whereas the performance of sodium, potassium and chloride were unsatisfactory, according to TEa’s of CLIA, Ricos and Rilibak.Conclusion:Since most of our sigma values were found to be over 3, the analytical performance of clinical chemistry tests was thought to be acceptable and our laboratory can be regarded as a qualified emergency laboratory.


Author(s):  
Carmen Perich ◽  
Carmen Ricós ◽  
Fernando Marqués ◽  
Joana Minchinela ◽  
Angel Salas ◽  
...  

AbstractThe purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQCML) external quality assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA–SEQCML programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.


2020 ◽  
Vol 45 (5) ◽  
pp. 491-498
Author(s):  
Fatih Yesildal ◽  
Ferruh Kemal Isman

AbstractObjectiveCOVID-19 pandemia still continues to threaten the whole world. High dose ascorbic acid (AA) infusion is a choice of treatment and its efficiency is still being investigated. AA interferes with many clinical chemistry tests. However, data about the interference of high concentrations of AA is not sufficient. In this study, we aimed to investigate the interference of AA at high concentrations on commonly used chemistry assays.Materials and MethodsSerum samples at AA concentrations of 200, 150, 100, 75, 50, 25, 10, 5, 2 and 0 mg/dL were prepared by using the stock solution of 15000 mg/dL AA. Each sample was analyzed by using the most common 30 chemistry tests (Abbott Architect C8000, Illinois, USA) and a POCT glucometer (STANDARD GlucoNavii, Gyeonggi-do, Republic of Korea).ResultsCreatinine, sodium and glucose (POCT) tests were found to be positively interfered by increasing AA concentrations; while direct bilirubin, lipase, UIBC, triglyceride, total cholesterol, HDL/LDL cholesterol tests were negatively interfered. Absolute interference (%) increased as the AA concentration increased.ConclusionThis is the largest and first study to investigate the interference of high dose AA, which is used in severe COVID-19 patients nowadays. Manufacturers and clinicians should be aware of the possibility of aberrant results due to high dose AA infusion. Clinicians should not forget to consult a laboratory specialist, since he is the only person to monitor the reactions in all assays, and know the technical subjects like interferences, assay method specifications. This issue is very important for correct decision-making and interpretation of the data-mining studies accurately and efficiently.


2018 ◽  
Vol 50 (1) ◽  
pp. e1-e8 ◽  
Author(s):  
Magdalena Krintus ◽  
Jon Ardanza Fernandez ◽  
Christine Chesters ◽  
Rossana Colla ◽  
Clare Ford ◽  
...  

Author(s):  
Sheila X. Soh ◽  
Tze Ping Loh ◽  
Sunil K. Sethi ◽  
Lizhen Ong

Abstract Objectives Lipemia is the presence of abnormally high lipoprotein concentrations in serum or plasma samples that can interfere with laboratory testing. There is little guidance available from manufacturers or professional bodies on processing lipemic samples to produce clinically acceptable results. This systematic review summarizes existing literature on the effectiveness of lipid removal techniques in reducing interference in clinical chemistry tests. Methods A PubMed search using terms relating to lipid removal from human samples for clinical chemistry tests produced 1,558 studies published between January 2010 and July 2021. 15 articles met the criteria for further analyses. Results A total of 66 analytes were investigated amongst the 15 studies, which showed highly heterogenous study designs. High-speed centrifugation was consistently effective for 13 analytes: albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, creatine kinase (CK), creatinine (Jaffe method), gamma-glutamyl transferase (GGT), glucose (hexokinase-based method), lactate dehydrogenase (LDH), phosphate, potassium, and urea. Lipid-clearing agents were uniformly effective for seven analytes: ALT, AST, total bilirubin, CK, creatinine (Jaffe method), lipase, and urea. Mixed results were reported for the remaining analytes. Conclusions For some analytes, high-speed centrifugation and/or lipid-clearing agents can be used in place of ultracentrifugation. Harmonized protocols and acceptability criteria are required to allow pooled data analysis and interpretation of different lipemic interference studies.


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