Robust estimation of between and within laboratory standard deviation with measurement results below the detection limit
In method validation studies, the question arises how to deal with < LOD results in order to ensure reliable precision estimates. It is proposed to elaborate strategies for dealing with < LOD results on the basis of the Q/Hampel method, a particularly robust statistical method. Two different s...
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Published in | Journal für Verbraucherschutz und Lebensmittelsicherheit Vol. 10; no. 4; pp. 385 - 391 |
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Main Author | |
Format | Journal Article |
Language | German |
Published |
Basel
Springer Basel
01.12.2015
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Subjects | |
Online Access | Get full text |
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Summary: | In method validation studies, the question arises how to deal with <
LOD
results in order to ensure reliable precision estimates. It is proposed to elaborate strategies for dealing with <
LOD
results on the basis of the Q/Hampel method, a particularly robust statistical method. Two different strategies are presented and assessed: censoring <
LOD
results and setting them equal to
LOD/2
. The two strategies are then examined in the light of the reliability of the precision estimates obtained on the basis of a comprehensive simulation study. The first method exhibits better precision, while the second method displays better trueness. However, the two methods are only satisfactory as long as the percentage of <
LOD
results is less than 25 %. For higher percentages of <
LOD
results, more sophisticated methods should be applied. |
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ISSN: | 1661-5751 1661-5867 |
DOI: | 10.1007/s00003-015-0967-3 |