The importance of internal quality control data in national external quality assessment schemes. Plasma progesterone assays

1983 ◽  
Vol 2 (2) ◽  
pp. 123-129 ◽  
Author(s):  
C. Kay ◽  
K. W. Kemp ◽  
A. B. J. Nix ◽  
R. J. Rowlands ◽  
G. V. Groom ◽  
...  
Keyword(s):  
Quality Control ◽  
Quality Assessment ◽  
External Quality Assessment ◽  
Internal Quality Control ◽  
Internal Quality ◽  
External Quality ◽  
Control Data ◽  
Plasma Progesterone ◽  
Quality Control Data

Applicability of various quality-control sera to assay of high-density lipoprotein cholesterol.

1980 ◽  
Vol 26 (7) ◽  
pp. 903-907
Author(s):  
D G Bullock ◽  
T J Carter ◽  
S V Hughes
Keyword(s):  
Quality Control ◽  
High Density Lipoprotein ◽  
Quality Assessment ◽  
High Density Lipoprotein Cholesterol ◽  
External Quality Assessment ◽  
Density Lipoprotein ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Internal Quality ◽  
External Quality

Abstract Effective internal quality control and external quality assessment of high-density lipoprotein cholesterol assay is made difficult by analyte instability, and the suitability of quality-control sera for this purpose has not been studied. We have therefore investigated the properties of 25 different control sera from 15 suppliers by estimating within-batch precision for the two precipitation procedures used most widely (phosphotungstate/Mg2+ and heparin/Mn2+ with enzymic measurement of cholesterol. Some sera had properties similar to those of fresh human serum, but others demonstrated poor precision for one or both procedures or contained apparent high-density lipoprotein cholesterol in unphysiological concentrations. A study of six sera indicated that between-batch precision was consistent with the within-batch findings. We found that eight of the 25 batches of quality-control serum we investigated may be used for internal quality control and external quality assessment of high-density lipoprotein cholesterol assay.

The application of Six Sigma to perform quality analyses of plasma proteins

2019 ◽  
Vol 57 (2) ◽  
pp. 121-127
Author(s):  
Fumeng Yang ◽  
Wenjun Wang ◽  
Qian Liu ◽  
Xizhen Wang ◽  
Guangrong Bian ◽  
...  
Keyword(s):  
Quality Control ◽  
Quality Assessment ◽  
Six Sigma ◽  
Plasma Proteins ◽  
External Quality Assessment ◽  
Internal Quality ◽  
C Reactive Protein ◽  
External Quality ◽  
Reactive Protein ◽  
Assessment Standards

Background The Six Sigma theory is an important tool for laboratory quality management. It has been widely used in clinical chemistry, haematology and other disciplines. The aim of our study was to evaluate the analytical performance of plasma proteins by application of Sigma metric and to compare the differences among three different allowable total errors in evaluating the analytical performance of plasma proteins. Methods Three different allowable total error values were used as quality goals. Data from an external quality assessment were used as bias, and the cumulative coefficient of variation in internal quality control data was used to represent the amount of imprecision during the same period. Sigma metric of analytes was calculated using the above data. The quality goal index was calculated to provide corrected measures for continuous improvements in analytical quality. Results The Sigma metric was highest using the external quality assessment standards of China: it was sigma ≥6 or higher in 57.1% of plasma proteins. But Sigma metric was lower by using RiliBÄK or biological variation standards. IgG, C3 and C-reactive protein all required quality improvements in imprecision. A single-rule 13s for internal quality control was recommended for IgA, IgM, C4 and rheumatoid factor, whereas multiple rules (13s/22s/R4s) were recommended for IgG, C3 and C-reactive protein, according to the external quality assessment standards of China. Conclusions Different quality goals can lead to different Sigma metric for the same analyte. As the lowest acceptable standard in clinical practice, the external quality assessment standard of China can guide laboratories to formulate reasonable quality improvement programmes.

Quality assurance in laboratory haematology

1993 ◽  
Vol 101 ◽  
pp. 283-310
Author(s):  
S. M. Lewis
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Quality Assessment ◽  
Blood Count ◽  
External Quality Assessment ◽  
Blood Film ◽  
Test Reliability ◽  
Internal Quality ◽  
External Quality ◽  
External Quality Assessment Scheme

SynopsisQuality assurance in laboratory haematology includes (a) constant checking of test reliability by internal quality control, (b) external quality assessment by an independent agency to check performance of a number of laboratories at intervals in order to obtain a retrospective indication of their ability and (c) proficiency control by supervision of the pre-test and post-test phases of laboratory work, from specimen collection to delivery of the report to the clinician.The procedures which comprise quality control are described; these include use of control preparations with control charts, CUSUM analysis, constancy of daily means of the blood count indices of ‘absolute values’, duplicate testing, clinical correlation and the important role of the blood film to check the instrument-derived blood count measurements.A description of the functions of an external quality assessment scheme is based on the UK National Scheme (UK NEQAS). The blood count and other tests of general haematology have been used as models to describe the procedures for qualitative and quantitative tests, low results are analysed and performance is assessed. The tribulations and triumphs of NEQAS are described and it is concluded that NEQAS has a vital role in ensuring good laboratory practice in general, and the reliability of the individual laboratories who participate in the scheme. NEQAS, in turn, must ensure its own ability to provide stable materials which are suitable for each test in the programme, and to analyse data correctly. There is also need to take account of the continued expansion of laboratory services as new techniques are introduced and to develop appropriate EQA procedures and materials in order to incorporate these in a comprehensive scheme.

External Quality Assessment of Serum Alpha-Fetoprotein Assays

1980 ◽  
Vol 17 (6) ◽  
pp. 332-333 ◽  
Author(s):  
J S Woodhead ◽  
Heather A Kemp ◽  
A B J Nix ◽  
R J Rowlands
Keyword(s):  
Quality Control ◽  
Quality Assessment ◽  
Neural Tube ◽  
External Quality Assessment ◽  
Maternal Serum ◽  
Alpha Fetoprotein ◽  
Internal Quality ◽  
External Quality ◽  
Individual Laboratory ◽  
Serum Alpha Fetoprotein

Adequate control of performance in immunoassays of maternal serum alpha-fetoprotein is an essential part of screening for neural tube defects. Information derived from external quality assessment schemes may be of limited value in monitoring individual laboratory performance and stresses the need for proper internal quality control.

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