breslow.dat {robust}

Breslow Data

Description

Patients suffering from simple or complex partial seizures were randomized to receive either the antiepileptic drug progabide or a placebo. At each of four successive postrandomization clinic visits, the number of seizures occuring over the previous two weeks was reported.

Usage

data(breslow.dat)

Format

A data frame with 59 observations on the following 12 variables.

ID

an integer value specifying the patient identification number.

Y1

an integer value, the number of seizures during the first two week period.

Y2

an integer value, the number of seizures during the second two week period.

Y3

an integer value, the number of seizures during the third two week period.

Y4

an integer value, the number of seizures during the fourth two week period.

Base

an integer value giving the eight-week baseline seizure count.

Age

an integer value giving the age of the parient in years.

Trt

the treatment: a factor with levels placebo and progabide.

Ysum

an integer value, the sum of Y1, Y2, Y3 and Y4.

sumY

an integer value, the sum of Y1, Y2, Y3 and Y4.

Age10

a numeric value, Age divided by 10.

Base4

a numeric value, Base divided by 4.

References

Breslow, N. E., and Clayton, D. G. (1993), "Approximate Inference in Generalized Linear Mixed Models," Journal of the American Statistical Association, Vol. 88, No. 421, pp. 9-25.

Thrall, P. F., and Vail, S. C. (1990), "Some Covariance Models for Longitudinal Count Data With Overdispersion," Biometrics, Vol. 46, pp. 657-671.

Examples

data(breslow.dat)