epilepsy: Seizure counts for 59 epileptics
In ALA: Data sets and examples for the book "Applied Longitudinal Analysis"

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The data are from a placebo-controlled clinical trial of 59 epileptics. Patients with partial seizures were enrolled in a randomized clinical trial of the anti-epileptic drug, progabide.

1	data(epilepsy)

A data frame with 295 observations on the following 5 variables.

id: a factor with 59 levels
treatment: a factor with levels placebo and progabide
age: a numeric vector
week: a numeric vector; 0 represents the baseline over the preceeding 8 weeks
nSeizures: a numeric vector; number of seizures

Participants in the study were randomized to either progabide or a placebo, as an adjuvant to the standard anti-epileptic chemotherapy. Progabide is an anti-epileptic drug whose primary mechanism of action is to enhance gamma-aminobutyric acid (GABA) content; GABA is the primary inhibitory neurotransmitter in the brain. Prior to receiving treatment, baseline data on the number of epileptic seizures during the preceding 8-week interval were recorded. Counts of epileptic seizures during 2-week intervals before each of four successive post-randomization clinic visits were recorded.

Original variable names have been adapted to R conventions. Data were reshaped from wide to long format and the response named nSeizures.

http://biosun1.harvard.edu/~fitzmaur/ala

Thall PF, Vail SC (1990) Some covariance models for longitudinal count data with overdispersion. Biometrics 46:657-671