Traceable assigned values in external quality assessment schemes compared to those obtained by alternative procedure: a case study for Cu, Se and Zn in serum

2015 ◽  
Vol 30 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marina Patriarca ◽  
Cas Weykamp ◽  
Josiane Arnaud ◽  
Robert L. Jones ◽  
Patrick J. Parsons ◽  
...  

International standards for the recognition of the competence of testing laboratories require that measurement results should be traceable to a conventionally agreed reference.

Author(s):  
Jin-Sook Wang ◽  
Mee-Kyung Kee ◽  
Byeong-Sun Choi ◽  
Chan-Wha Kim ◽  
Hyon-Suk Kim ◽  
...  

AbstractThe external quality assessment schemes (EQAS) organizer provides a suitable program to monitor and improve the quality of human immunodeficiency virus (HIV) testing laboratories with EQAS panels prepared under various conditions. The aim of the current study was to investigate the effects of human plasma samples on the EQAS results of HIV obtained from hospital-based clinical laboratories.From 2007 to 2009, HIV EQAS panels consisted of four to six samples that consisted of undiluted positive and negative samples and were provided to laboratories twice per year. Up until the first half EQAS in 2008, EQAS panel materials were obtained by converting acid citrate dextrose treated plasma to serum via chemical treatment with CaClApproximately 300 HIV clinical laboratories participated in this program. The overall performance of clinical laboratories was shown to be improved when using unrecalcified plasma panels compared with recalcified panels. Significant differences were observed in EIA analyses of plasma for both positive (p<0.001) and negative (p<0.001) samples between the recalcified and unrecalcified groups.Our finding suggested that defibrination status of EQAS panels might affect the results of anti-HIV EQAS of Korean HIV testing laboratories.


2018 ◽  
Vol 56 (5) ◽  
pp. 789-795 ◽  
Author(s):  
Jie Zeng ◽  
Tianqi Qi ◽  
Shu Wang ◽  
Tianjiao Zhang ◽  
Weiyan Zhou ◽  
...  

AbstractBackground:The aim of the current study was to evaluate the commutability of commercial control materials and human serum pools and to investigate the suitability of the materials for the external quality assessment (EQA) of serum apolipoprotein A-I (apo A-I) measurement.Methods:The Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol was used for the commutability study. Apo A-I concentrations in two levels of commercial control materials used in EQA program, two fresh-frozen human serum pools (FSPs) and two frozen human serum pools prepared from residual clinical specimens (RSPs) were measured along with 50 individual samples using nine commercial assays. Measurement results of the 50 individual samples obtained with different assays were pairwise analyzed by Deming regression, and 95% prediction intervals (PIs) were calculated. The commutability of the processed materials was evaluated by comparing the measurement results of the materials with the limits of the PIs.Results:The FSP-1 was commutable for all the 36 assay pairs, and FSP-2 was commutable for 30 pairs; RSP-1 and RSP-2 showed commutability for 27/36 and 22/36 assay pairs, respectively, whereas the two EQA materials were commutable only for 4/36 and 5/36 assay pairs, respectively.Conclusions:Non-commutability of the tested EQA materials has been observed among current apo A-I assays. EQA programs need either to take into account the commutability-related biases in the interpretation of the EQA results or to use more commutable materials. Frozen human serum pools were commutable for most of the assays.


2018 ◽  
Vol 56 (10) ◽  
pp. 1644-1654 ◽  
Author(s):  
Laura Sciacovelli ◽  
Sandra Secchiero ◽  
Andrea Padoan ◽  
Mario Plebani

Abstract Effective management of clinical laboratories participating in external quality assessment schemes (EQAS) is of fundamental importance in ensuring reliable analytical results. The International Standard ISO 15189:2012 requires participation in interlaboratory comparison [e.g. external quality assessment (EQA)] for all tests provided by an individual laboratory. If EQAS is not commercially available, alternative approaches should be identified, although clinical laboratories may find it challenging to choose the EQAS that comply with the international standards and approved guidelines. Great competence is therefore required, as well as knowledge of the characteristics and key elements affecting the reliability of an EQAS, and the analytical quality specifications stated in approved documents. Another skill of fundamental importance is the ability to identify an alternative approach when the available EQAS are inadequate or missing. Yet the choice of the right EQA program alone does not guarantee its effectiveness. In fact, the fundamental steps of analysis of the information provided in EQA reports and the ability to identify improvement actions to be undertaken call for the involvement of all laboratory staff playing a role in the specific activity. The aim of this paper was to describe the critical aspects that EQA providers and laboratory professionals should control in order to guarantee effective EQAS management and compliance with ISO 15189 accreditation requirements.


2013 ◽  
Vol 59 (9) ◽  
pp. 1322-1329 ◽  
Author(s):  
Ingrid Zegers ◽  
Robert Beetham ◽  
Thomas Keller ◽  
Joanna Sheldon ◽  
David Bullock ◽  
...  

BACKGROUND Different methods for ceruloplasmin tend to give different results in external quality assessment schemes. During the production of the certified reference material ERM-DA470k/IFCC discrepant measurement results were also found for ceruloplasmin measured with different methods, and consequently the protein could not be certified in the material. METHODS We performed a commutability study with 30 serum samples and the reference materials ERM-DA470, ERM-DA470k/IFCC, and ERM-DA472/IFCC, using 6 different methods. Data were analyzed according to the CLSI Guideline C53-A to assess whether the reference materials had the same behavior as the serum samples with respect to measurement results obtained with combinations of the methods used. RESULTS Measurement results from different methods showed a good linear correlation for the serum samples. ERM-DA470 showed marked noncommutability for certain combinations of methods. ERM-DA470k/IFCC and ERM-DA472/IFCC were commutable for more combinations of methods. The lack of commutability of ERM-DA470 for certain combinations of methods correlates with results from the UK National External Quality Assessment Service showing discrepancies between results from these methods. For serum stored in the presence of sodium azide the results from different methods are essentially equivalent. CONCLUSIONS Ceruloplasmin in ERM-DA470 is a fully documented example of a situation in which, due to lack of commutability, the use of a common material for calibration did not lead to harmonization .


2011 ◽  
Vol 412 (11-12) ◽  
pp. 1127-1132 ◽  
Author(s):  
Jin-Sook Wang ◽  
Mee-Kyung Kee ◽  
Byeong-Sun Choi ◽  
Chan-Wha Kim ◽  
Sung Soon Kim

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