seizure {cold} | R Documentation |

## Epileptic Seizure

### Description

The dataset has the number of epileptic seizures in each of four two-week intervals, and in a baseline eight-week interval, for treatment and control groups with a total of 59 individuals.

### Usage

`data(seizure)`

### Format

A data frame with 236 observations on the following 9 variables.

`id`

identifies de number of the individual profile. This vector contains observations of 59 individual profiles.

`y`

a numeric vector with the number of epileptic seizures in the four two-weeks intervals observed.

`v4`

a numeric vector indicating the fourth visit.

`time`

a numeric vector that identifies the number of the time points observed.

`trt`

a numeric vector indicator of treatment, whether the patient is treated with placebo (

`trt=0`

) or progabide (`trt=1`

)

.

`base`

the number of epileptic seizures in a baseline 8-week interval.

`age`

a numeric vector of subject

`age`

.`lbase`

recode the variable

`base`

by log(`base`

/4).`lage`

recode the variable

`age`

by log(`age`

).

### 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., Heagerty, P., Liang, K.Y., and Zeger, S.L. (2002). Analysis of Longitudinal Data. 2nd edition. Oxford University Press.

### Examples

```
##### data = seizure
str(seizure)
### independence
seiz0M <- cold(y ~ lage + lbase + v4 + trt + trt:lbase, data = seizure,
dependence = "ind")
summary(seiz0M)
### AR1
seiz1M <- cold(y ~ lage + lbase + v4 + trt + trt:lbase, data = seizure,
dependence = "AR1")
summary(seiz1M)
anova(seiz0M, seiz1M)
```

*cold*version 2.0-3 Index]