seizure {cold} | R Documentation |
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.
data(seizure)
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
).
Thall, P.F., and Vail, S.C. (1990). Some covariance models for longitudinal count data with overdispersion. Biometrics, 46, 657–671.
Diggle, P.J., Heagerty, P., Liang, K.Y., and Zeger, S.L. (2002). Analysis of Longitudinal Data. 2nd edition. Oxford University Press.
##### 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)