Modified Levey-Jennings charts for calculated laboratory tests
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Abdurrahman Coskun
Abstract
Background: In clinical laboratories, many test results such as low-density lipoproteins can be calculated using the results of specifically measured tests. However, quality control programs deal with only measured tests and there is no quality control procedure for calculated tests. I aimed to modify the Levey-Jennings chart for calculated tests as part of a total quality system.
Methods: I developed a method using a Taylor series expansion and alternative equations to obtain the standard deviation of calculated tests and then prepared Levey-Jennings charts for these tests.
Results: Preparation of Levey-Jennings charts for low-density lipoproteins (and other calculated tests) was simple, and using this chart increased the reliability of calculated test results.
Conclusion: Checking only measured tests by quality control procedures before reporting patient results may be inadequate. Preparation of Levey-Jennings charts for calculated tests as part of total quality management will increase the reliability of test results.
References
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©2006 by Walter de Gruyter Berlin New York
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Articles in the same Issue
- Natriuretic peptides and evidence-based quality specifications
- Preanalytical variability: the dark side of the moon in laboratory testing
- Clinical relevance of biological variation: the lesson of brain natriuretic peptide (BNP) and NT-proBNP assay
- Hepatorenal syndrome
- Modified Levey-Jennings charts for calculated laboratory tests
- Increased free malondialdehyde concentrations in smokers normalise with a mixed fruit and vegetable juice concentrate: a pilot study
- The exponentially weighted moving average (EWMA) rule compared with traditionally used quality control rules
- Intermethod calibration of alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) results: application to Fibrotest® and Actitest® scores
- Comparison of TEST 1 with SRS 100 and ICSH reference method for the measurement of the length of sedimentation reaction in blood
- Multicenter evaluation of the interference of hemoglobin, bilirubin and lipids on Synchron LX-20 assays
- Technical evaluation of the Beckman Coulter OV-Monitor (CA 125 antigen) immunoassay
- Erythrocyte membrane Na+,K+-ATPase and Mg2+-ATPase activities in subjects with methylenetetrahydrofolate reductase (MTHFR) 677 C→T genotype and moderate hyperhomocysteinaemia. The role of L-phenylalanine and L-alanine
- Matrix metalloproteinases and their inhibitors in different acute stroke subtypes
- Pyrosequencing protocol requiring a unique biotinylated primer
- Detection of antibodies against 60-, 65- and 70-kDa heat shock proteins in paediatric patients with various disorders using Western blotting and ELISA
- Quantitative determination of erythrocyte folate vitamer distribution by liquid chromatography-tandem mass spectrometry
- Time-level relationship between indicators of oxidative stress and Glasgow Coma Scale scores of severe head injury patients
- Stepwise strategies in analysing haematuria and leukocyturia in screening
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