R Dataset / Package robustbase / epilepsy
On this Rdata statistics page, you will find information about the epilepsy data set which pertains to Epilepsy Attacks Data Set. The epilepsy data set is found in the robustbase R package. You can load the epilepsy data set in R by issuing the following command at the console data("epilepsy"). This will load the data into a variable called epilepsy. If R says the epilepsy data set is not found, you can try installing the package by issuing this command install.packages("robustbase") and then attempt to reload the data with the library() command. If you need to download R, you can go to the R project website. You can download a CSV (comma separated values) version of the epilepsy R data set. The size of this file is about 6,683 bytes.
Epilepsy Attacks Data Set
Description
Data from a clinical trial of 59 patients with epilepsy (Breslow, 1996) in order to illustrate diagnostic techniques in Poisson regression.
Usage
data(epilepsy)
Format
A data frame with 59 observations on the following 11 variables.
ID

Patient identification number
Y1

Number of epilepsy attacks patients have during the first followup period
Y2

Number of epilepsy attacks patients have during the second followup period
Y3

Number of epilepsy attacks patients have during the third followup period
Y4

Number of epilepsy attacks patients have during the forth followup period
Base

Number of epileptic attacks recorded during 8 week period prior to randomization
Age

Age of the patients
Trt

a factor with levels
placebo
progabide
indicating whether the antiepilepsy drug Progabide has been applied or not Ysum

Total number of epilepsy attacks patients have during the four followup periods
Age10

Age of the patients devided by 10
Base4

Variable
Base
devided by 4
Details
Thall and Vail reported data from a clinical trial of 59 patients with epilepsy, 31 of whom were randomized to receive the antiepilepsy drug Progabide and 28 of whom received a placebo. Baseline data consisted of the patient's age and the number of epileptic seizures recorded during 8 week period prior to randomization. The response consisted of counts of seizures occuring during the four consecutive followup periods of two weeks each.
Source
Thall, P.F. and Vail S.C. (1990) Some covariance models for longitudinal count data with overdispersion. Biometrics 46, 657–671.
References
Diggle, P.J., Liang, K.Y., and Zeger, S.L. (1994) Analysis of Longitudinal Data; Clarendon Press.
Breslow N. E. (1996) Generalized linear models: Checking assumptions and strengthening conclusions. Statistica Applicata 8, 23–41.
Examples
data(epilepsy) str(epilepsy) pairs(epilepsy[,c("Ysum","Base4","Trt","Age10")])Efit1 < glm(Ysum ~ Age10 + Base4*Trt, family=poisson, data=epilepsy) summary(Efit1)## Robust Fit : Efit2 < glmrob(Ysum ~ Age10 + Base4*Trt, family=poisson, data=epilepsy, method = "Mqle", tcc=1.2, maxit=100) summary(Efit2)
Dataset imported from https://www.rproject.org.