R: Rodent bronchial carcinoma data

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)

[Package MCPAN version 1.1-21 Index]