downs {GLMsData}

Downs Syndrome cases in British Columbia

Description

The number of Downs Syndrome cases in British Columbia, Canada

Usage

data(downs)

Format

A data frame with 30 observations on the following 3 variables.

Age

the average age of the mother in each group, in completed years; a numeric vector

Births

the number of live births; a numeric vector

DS

the number of Downs Syndrome births; a numeric vector

Details

The data give the number of Downs Syndrome cases from 1961–1970 in British Columbia, Canada, in 30 age categories for the mother.

Note

The ages are the means of the ages in defined groups, rounded to one decimal place.

Source

Charles J. Geyer (1991) Constrained maximum likelihood exemplified by isotonic convex logistic regression. Journal of the American Statistical Association, 86(415), 717–724.

References

The data are originally from the British Columbia Health Surveillance Registry.

The data also appear in A. C. Davison and D. V. Hinkley (1997) Bootstrap Methods and their Applications, Cambridge University Press, Table 7.12, though there are very slight differences in their data to ours, in the decimal places for age. (The differences are very minor, and will not affect conclusions.)

Examples

	data(downs)
	plot( DS/Births ~ Age, data=downs)