asat {coin} | R Documentation |
Measurements of the liver enzyme aspartate aminotransferase (ASAT) for a new compound and a control group of 34 female Wistar rats.
asat
A data frame with 34 observations on 2 variables.
asat
ASAT values.
group
a factor with levels "Compound"
and "Control"
.
The aim of this toxicological study is the proof of safety for the new compound. The data were originally given in Hothorn (1992) and later reproduced by Hauschke, Kieser and Hothorn (1999).
Hauschke, D., Kieser, M. and Hothorn, L. A. (1999). Proof of safety in toxicology based on the ratio of two means for normally distributed data. Biometrical Journal 41(3), 295–304. doi: 10.1002/(SICI)1521-4036(199906)41:3<295::AID-BIMJ295>3.0.CO;2-2
Hothorn, L. A. (1992). Biometrische analyse toxikologischer untersuchungen. In J. Adam (Ed.), Statistisches Know-How in der Medizinischen Forschung, pp. 475–590. Berlin: Ullstein Mosby.
Pflüger, R. and Hothorn, T. (2002). Assessing equivalence
tests with respect to their expected p
-value. Biometrical
Journal 44(8), 1015–1027. doi: 10.1002/bimj.200290001
## Proof-of-safety based on ratio of medians (Pflueger and Hothorn, 2002)
## One-sided exact Wilcoxon-Mann-Whitney test
wt <- wilcox_test(I(log(asat)) ~ group, data = asat,
distribution = "exact", alternative = "less",
conf.int = TRUE)
## One-sided confidence set
## Note: Safety cannot be concluded since the effect of the compound
## exceeds 20 % of the control median
exp(confint(wt)$conf.int)