Journal Information
Journal ID (publisher-id): BM
Journal ID (nlm-ta): Biochem Med (Zagreb)
Title: Biochemia Medica
Abbreviated Title: Biochem. Med. (Zagreb)
ISSN (print): 1330-0962
ISSN (electronic): 1846-7482
Publisher: Croatian Society of Medical Biochemistry and Laboratory Medicine
Article Information
Copyright statement: Croatian Society of Medical Biochemistry and Laboratory Medicine.
Copyright: 2017, Croatian Society of Medical Biochemistry
License (open-access):
This is an Open Access article distributed under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Date received: 01 December 2017
Date accepted: 13 March 2018
Publication date (print and electronic): 15 June 2018
Volume: 28
Issue: 2
Electronic Location Identifier: 020708
Publisher ID: bm-28-2-020708
DOI: 10.11613/BM.2018.020708
Sigma metrics for assessing the analytical quality of clinical chemistry assays: a comparison of two approaches:
Electronic supplementary material available online for this article.
Xiuzhi Guo[1]
Tianjiao Zhang[2]
Xuehui Gao[1]
Pengchang Li[1]
Tingting You[1]
Qiong Wu[3]
Jie Wu[1]
Fang Zhao[1]
Liangyu Xia[1]
Ermu Xu[1]
Ling Qiu[1]
[1] Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academic Medical Science and Peking Union Medical College, Beijing, P.R. China
[2] National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China
[3] Clinical Laboratory, Affiliated Hospital of Chifeng University, Inner Mongolia, P.R. China
Author notes:
Introduction
Two approaches were compared for the calculation of coefficient of variation (CV) and bias, and their effect on sigma calculation, when different allowable total error (TEa) values were used to determine the optimal method for Six Sigma quality management in the clinical laboratory.
Materials and methods
Sigma metrics for routine clinical chemistry tests using three systems (Beckman AU5800, Roche C8000, Siemens Dimension) were determined in June 2017 in the laboratory of Peking Union Medical College Hospital. Imprecision (CV%) and bias (bias%) were calculated for ten routine clinical chemistry tests using a proficiency testing (PT)- or an internal quality control (IQC)-based approach. Allowable total error from the Clinical Laboratory Improvement Amendments of 1988 and the Chinese Ministry of Health Clinical Laboratory Center Industry Standard (WS/T403-2012) were used with the formula: Sigma = (TEa − bias) / CV to calculate the Sigma metrics (σCLIA, σWS/T) for each assay for comparative analysis.
Results
For the PT-based approach, eight assays on the Beckman AU5800 system, seven assays on the Roche C8000 system and six assays on the Siemens Dimension system showed σCLIA > 3. For the IQC-based approach, ten, nine and seven assays, respectively, showed σCLIA > 3. Some differences in σ were therefore observed between the two calculation methods and the different TEa values.
Keywords: Six Sigma; proficiency testing; internal quality control; allowable total error
