PMID- 24615486
OWN - NLM
STAT- MEDLINE
DCOM- 20150409
LR  - 20220408
IS  - 1437-4331 (Electronic)
IS  - 1434-6621 (Linking)
VI  - 52
IP  - 7
DP  - 2014 Jul
TI  - Sigma metrics used to assess analytical quality of clinical chemistry assays: 
      importance of the allowable total error (TEa) target.
PG  - 973-80
LID - 10.1515/cclm-2013-1090 [doi]
AB  - BACKGROUND: Six Sigma metrics were used to assess the analytical quality of 
      automated clinical chemistry and immunoassay tests in a large Belgian clinical 
      laboratory and to explore the importance of the source used for estimation of the 
      allowable total error. Clinical laboratories are continually challenged to 
      maintain analytical quality. However, it is difficult to measure assay quality 
      objectively and quantitatively. METHODS: The Sigma metric is a single number that 
      estimates quality based on the traditional parameters used in the clinical 
      laboratory: allowable total error (TEa), precision and bias. In this study, Sigma 
      metrics were calculated for 41 clinical chemistry assays for serum and urine on 
      five ARCHITECT c16000 chemistry analyzers. Controls at two analyte concentrations 
      were tested and Sigma metrics were calculated using three different TEa targets 
      (Ricos biological variability, CLIA, and RiliBAK). RESULTS: Sigma metrics varied 
      with analyte concentration, the TEa target, and between/among analyzers. Sigma 
      values identified those assays that are analytically robust and require minimal 
      quality control rules and those that exhibit more variability and require more 
      complex rules. The analyzer to analyzer variability was assessed on the basis of 
      Sigma metrics. CONCLUSIONS: Six Sigma is a more efficient way to control quality, 
      but the lack of TEa targets for many analytes and the sometimes inconsistent TEa 
      targets from different sources are important variables for the interpretation and 
      the application of Sigma metrics in a routine clinical laboratory. Sigma metrics 
      are a valuable means of comparing the analytical quality of two or more analyzers 
      to ensure the comparability of patient test results.
FAU - Hens, Koen
AU  - Hens K
FAU - Berth, Mario
AU  - Berth M
FAU - Armbruster, Dave
AU  - Armbruster D
FAU - Westgard, Sten
AU  - Westgard S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Clin Chem Lab Med
JT  - Clinical chemistry and laboratory medicine
JID - 9806306
SB  - IM
MH  - Clinical Chemistry Tests/*methods/*standards
MH  - Humans
MH  - Immunoassay
MH  - Quality Control
EDAT- 2014/03/13 06:00
MHDA- 2015/04/10 06:00
CRDT- 2014/03/12 06:00
PHST- 2013/12/17 00:00 [received]
PHST- 2014/02/17 00:00 [accepted]
PHST- 2014/03/12 06:00 [entrez]
PHST- 2014/03/13 06:00 [pubmed]
PHST- 2015/04/10 06:00 [medline]
AID - /j/cclm-ahead-of-print/cclm-2013-1090/cclm-2013-1090.xml [pii]
AID - 10.1515/cclm-2013-1090 [doi]
PST - ppublish
SO  - Clin Chem Lab Med. 2014 Jul;52(7):973-80. doi: 10.1515/cclm-2013-1090.