| bronch {MCPAN} | R Documentation |
Rodent bronchial carcinoma data
Description
In a long term rodent carcinogenicity study on female B6C3F1 mice, the effect of vinylcyclohexene diepoxide on the incidence of murine alveolar/bronchiolar tumors was assessed. The mice were exposed to 0 mg/ml, (group 0), 25 mg/ml (group 1), 50 mg/ml (group 2), and 100 (group 3) mg/ml, with 50 animals per group.
Usage
data(bronch)Format
A data frame with 200 observations on the following 3 variables.
- group
a factor with levels 0, 1, 2, 3, labelling the control and the three dose groups
- Y
a logical vector, indicating whether a tumour was present at time of death (if TRUE), or not (if FALSE)
- time
a numeric vector, the time of death, counted in days? from begin of the study
Details
Not yet checked for consistency with the source!
Source
Piegorsch WW and Bailer AJ (1997): Statistics for environmental biology and toxicology. Chapman and Hall, London. Table 6.5, page 238.
References
Portier cJ and Bailer AJ (1989): Testing for increased carcinogenicity using survival-adjusted quantal response tests. Fundamental and Applied Toxicology 12, 731.
Examples
data(bronch)
# raw tumour counts:
table(bronch[c("group","Y")])
# groupwise times of death:
boxplot(time ~ group, data=bronch, horizontal=TRUE)
# Using poly3estf, we can produce the
# summary statistics as presented in
# Table 6.6, page 239, of Piegorsch and Bailer (1997):
poly3estf(status=bronch$Y, time=bronch$time, f=bronch$group)