DPpackage (version 1.1-6)

psychiatric: Psychiatric Clinical Trial

Description

This data set consider information from a pychiatric clinical trial, reported by Hedeker and Gibbons (1994) and collected in the NIMH Schizophrenia Collaborative Study on treatment-related changes in overall severity. For each patient, the Impatient Multidimensional Psychiatric Scale was scored. In this study, 437 patients were randomly assigned to receive one of four medications: placebo, chlorpromazine, fluphenazine, or thioridazine.

Usage

data(psychiatric)

Format

A data frame with 1603 observations on the following 5 variables.

id

a numeric vector giving a unique identifier for the subject in the study

imps79o

a factor giving the Impatient Multidimensional Psuchiatric Scale scored as 1 = normal or borderline mentally ill, 2 = midly or moderately ill, 3 = markadely ill, and 4 = severely or among the the most extremely ill

tx

a numeric vector giving the treatment group, 0=Placebo, 1=Drug

week

a numeric vector giving the week where the measurement ocurred

sweek

a numeric vector giving the square root transformation of time

Source

Hedeker, D. and Gibbons, R.D. (1994) A random-effects ordinal regression model for multilevel data. Biometrics, 50: 933-944.

References

Hedeker, D. and Gibbons, R.D. (1994) A random-effects ordinal regression model for multilevel data. Biometrics, 50: 933-944.

Examples

data(psychiatric)
## maybe str(psychiatric) ; plot(psychiatric) ...