vcdExtra (version 0.8-5)

Toxaemia: Toxaemia Symptoms in Pregnancy

Description

Brown et al (1983) gave these data on two signs of toxaemia, an abnormal condition during pregnancy characterized by high blood pressure (hypertension) and high levels of protein in the urine. If untreated, both the mother and baby are at risk of complications or death.

The data frame Toxaemia represents 13384 expectant mothers in Bradford, England in their first pregnancy, who were also classified according to social class and the number of cigarettes smoked per day.

Usage

data(Toxaemia)

Format

A data frame in frequency form representing a 5 x 3 x 2 x 2 contingency table, with 60 observations on the following 5 variables.

class

Social class of mother, a factor with levels 1 2 3 4 5

smoke

Cigarettes smoked per day during pregnancy, a factor with levels 0 1-19 20+

hyper

Hypertension level, a factor with levels Low High

urea

Protein urea level, a factor with levels Low High

Freq

frequency in each cell, a numeric vector

References

Friendly, M. (2000), Visualizing Categorical Data, SAS Institute, Cary, NC, Example 7.15.

Friendly, M. and Meyer, D. (2016). Discrete Data Analysis with R: Visualization and Modeling Techniques for Categorical and Count Data. Boca Raton, FL: Chapman & Hall/CRC. http://ddar.datavis.ca. Example 10.10.

Examples

data(Toxaemia)

tox.tab <- xtabs(Freq ~ class + smoke + hyper + urea, Toxaemia)
ftable(tox.tab, row.vars=1)


# symptoms by smoking
mosaic(~smoke + hyper + urea, data=tox.tab, shade=TRUE)

# symptoms by social class
mosaic(~class + hyper + urea, data=tox.tab, shade=TRUE)

# predictors
mosaic(~smoke + class, data=tox.tab, shade=TRUE)

# responses
mosaic(~hyper + urea, data=tox.tab, shade=TRUE)

# log odds ratios for urea and hypertension, by class and smoke
if (FALSE) {
LOR <-loddsratio(aperm(tox.tab))
LOR
}