+------------+-------------------+
| epilepsy   | R Documentation   |
+------------+-------------------+

Epilepsy Data
-------------

Description
~~~~~~~~~~~

A randomised clinical trial investigating the effect of an
anti-epileptic drug.

Usage
~~~~~

::

    data("epilepsy")

Format
~~~~~~

A data frame with 236 observations on the following 6 variables.

``treatment``
    the treatment group, a factor with levels ``placebo`` and
    ``Progabide``.

``base``
    the number of seizures before the trial.

``age``
    the age of the patient.

``seizure.rate``
    the number of seizures (response variable).

``period``
    treatment period, an ordered factor with levels ``1`` to ``4``.

``subject``
    the patient ID, a factor with levels ``1`` to ``59``.

Details
~~~~~~~

In this clinical trial, 59 patients suffering from epilepsy were
randomized to groups receiving either the anti-epileptic drug Progabide
or a placebo in addition to standard chemotherapy. The numbers of
seizures suffered in each of four, two-week periods were recorded for
each patient along with a baseline seizure count for the 8 weeks prior
to being randomized to treatment and age. The main question of interest
is whether taking progabide reduced the number of epileptic seizures
compared with placebo.

Source
~~~~~~

P. F. Thall and S. C. Vail (1990), Some covariance models for
longitudinal count data with overdispersion. *Biometrics*, **46**,
657â€“671.

Examples
~~~~~~~~

::


      data("epilepsy", package = "HSAUR")
      library(lattice)
      dotplot(I(seizure.rate / base) ~ period | subject, data = epilepsy, 
              subset = treatment == "Progabide")
      dotplot(I(seizure.rate / base) ~ period | subject, data = epilepsy, 
              subset = treatment == "Progabide")

