Details
| Original language | English |
|---|---|
| Pages (from-to) | 1901-1910 |
| Number of pages | 10 |
| Journal | Archives of toxicology |
| Volume | 87 |
| Issue number | 11 |
| Publication status | Published - 8 May 2013 |
Abstract
The US National Toxicology Program recommends the use of the parametric multiple comparison procedures of Dunnett and Williams for the evaluation of repeated toxicity studies. For endpoints where either increasing or decreasing effects are of toxicological relevance, we recommend the use of the two-sided Dunnett test exclusively. For the many other endpoints, where a priori only one direction is of toxicological relevance, however, we recommend the combination of Dunnett and Williams test. In particular, we recommend the so-called Umbrella-protected Williams test which offers insights for all interesting monotone and non-monotone alternatives while only suffering a marginal loss in power compared to the Dunnett test. We illustrate the power difference analytically and compare the approach for different endpoint types using three real data examples to alternative tests available. Nonparametric tests, which are suitable for the evaluation of skewed distributed or scores data, are also considered. Particular attention is given to the different interpretations of the findings revealed by the different test. R programs used for the analyses are provided.
Keywords
- Dunnett test, Multiple comparisons, R program, Repeated toxicity studies, Umbrella alternative, Williams test
ASJC Scopus subject areas
- Pharmacology, Toxicology and Pharmaceutics(all)
- Toxicology
- Environmental Science(all)
- Health, Toxicology and Mutagenesis
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In: Archives of toxicology, Vol. 87, No. 11, 08.05.2013, p. 1901-1910.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Statistical evaluation of toxicological assays
T2 - Dunnett or Williams test - Take both
AU - Jaki, Thomas
AU - Hothorn, Ludwig A.
N1 - Funding Information: Acknowledgments This work was supported in part by the German Science Foundation grant DfG-HO1687 and the EC FP7 program project ESNATS for the last author (LAH).
PY - 2013/5/8
Y1 - 2013/5/8
N2 - The US National Toxicology Program recommends the use of the parametric multiple comparison procedures of Dunnett and Williams for the evaluation of repeated toxicity studies. For endpoints where either increasing or decreasing effects are of toxicological relevance, we recommend the use of the two-sided Dunnett test exclusively. For the many other endpoints, where a priori only one direction is of toxicological relevance, however, we recommend the combination of Dunnett and Williams test. In particular, we recommend the so-called Umbrella-protected Williams test which offers insights for all interesting monotone and non-monotone alternatives while only suffering a marginal loss in power compared to the Dunnett test. We illustrate the power difference analytically and compare the approach for different endpoint types using three real data examples to alternative tests available. Nonparametric tests, which are suitable for the evaluation of skewed distributed or scores data, are also considered. Particular attention is given to the different interpretations of the findings revealed by the different test. R programs used for the analyses are provided.
AB - The US National Toxicology Program recommends the use of the parametric multiple comparison procedures of Dunnett and Williams for the evaluation of repeated toxicity studies. For endpoints where either increasing or decreasing effects are of toxicological relevance, we recommend the use of the two-sided Dunnett test exclusively. For the many other endpoints, where a priori only one direction is of toxicological relevance, however, we recommend the combination of Dunnett and Williams test. In particular, we recommend the so-called Umbrella-protected Williams test which offers insights for all interesting monotone and non-monotone alternatives while only suffering a marginal loss in power compared to the Dunnett test. We illustrate the power difference analytically and compare the approach for different endpoint types using three real data examples to alternative tests available. Nonparametric tests, which are suitable for the evaluation of skewed distributed or scores data, are also considered. Particular attention is given to the different interpretations of the findings revealed by the different test. R programs used for the analyses are provided.
KW - Dunnett test
KW - Multiple comparisons
KW - R program
KW - Repeated toxicity studies
KW - Umbrella alternative
KW - Williams test
UR - http://www.scopus.com/inward/record.url?scp=84886903839&partnerID=8YFLogxK
U2 - 10.1007/s00204-013-1065-x
DO - 10.1007/s00204-013-1065-x
M3 - Article
C2 - 23652543
AN - SCOPUS:84886903839
VL - 87
SP - 1901
EP - 1910
JO - Archives of toxicology
JF - Archives of toxicology
SN - 0340-5761
IS - 11
ER -