|
|
||||||||
Clinical Chemistry, Vol 25, 675-677, Copyright © 1979 by American Association for Clinical Chemistry
MJ Healy
Results submitted to large-scale quality-control schemes are commonly judged against the mean and standard deviation (SD) of the results from other laboratories. It is desirable to ignore outlying values in estimating this mean and standard deviation, and results more than 2.5 or 3 SD from the mean are commonly rejected. I show that an outlier can so inflate the estimated SD that its presence is not detected by this method. Alternative estimators that are less influenced by outliers are described, and their application to quality-control data is discussed.
The following articles in journals at HighWire Press have cited this article:
![]() |
J. F. Wilson and K. Barnett Variation with Time in Components of Variance for Measurements of Therapeutic Drugs Clin. Chem., December 1, 2005; 51(12): 2385 - 2387. [Full Text] [PDF] |
||||
![]() |
G. D. Carter, R. Carter, J. Jones, and J. Berry How Accurate Are Assays for 25-Hydroxyvitamin D? Data from the International Vitamin D External Quality Assessment Scheme Clin. Chem., November 1, 2004; 50(11): 2195 - 2197. [Full Text] [PDF] |
||||
![]() |
D. L. Witte, S. A. VanNess, D. S. Angstadt, and B. J. Pennell Errors, mistakes, blunders, outliers, or unacceptable results: how many? Clin. Chem., August 1, 1997; 43(8): 1352 - 1356. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |