| Error models for immunoassays. | |
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MedLine Citation:
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PMID: 18753420 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: For nearly 20 years, we and others have used a three-parameter power function as a direct estimation error model for immunoassays. The main application is imprecision profile plots (after translating from variance to coefficient of variation) but other uses include weighting functions for regression analysis and variance stabilizing transformations. Although generally successful, the intrinsic monotonicity of the function means that it fails to describe small but distinct increases in variance that occasionally occur near the assay detection limit. METHODS: A systematic comparison of five variance functions was undertaken, using randomly drawn samples from a large body of real immunoassay data. RESULTS: Variance function accuracy (hence imprecision profile accuracy) can be markedly improved, particularly near the assay detection limit, by employing a pair of complementary three-parameter power functions, together with a constrained four-parameter function, which provides for a variance turning point. CONCLUSIONS: A set of rules, based on an objective goodness-of-fit statistic, can be used to automate presentation of the most appropriate function for any particular data-set. Flexibility is easily incorporated into the selection rules and is actually highly desirable to encourage ongoing evaluation with a wider variety of data. A Win32 computer program that performs the variance function estimation and plotting is freely available. |
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Authors:
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William A Sadler |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Annals of clinical biochemistry Volume: 45 ISSN: 0004-5632 ISO Abbreviation: Ann. Clin. Biochem. Publication Date: 2008 Sep |
Date Detail:
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Created Date: 2008-08-28 Completed Date: 2008-11-13 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0324055 Medline TA: Ann Clin Biochem Country: England |
Other Details:
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Languages: eng Pagination: 481-5 Citation Subset: IM |
Affiliation:
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Department of Nuclear Medicine, Christchurch Hospital, Christchurch, New Zealand. bill.sadler@xtra.co.nz |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Algorithms C-Reactive Protein / analysis Chemistry, Clinical / methods Computers Humans Immunoassay / methods* Mathematical Computing Models, Statistical Models, Theoretical Numerical Analysis, Computer-Assisted Radioimmunoassay / methods Regression Analysis Reproducibility of Results Software Thyroxine / chemistry |
| Chemical | |
Reg. No./Substance:
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7488-70-2/Thyroxine; 9007-41-4/C-Reactive Protein |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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