backPain {VGAM} | R Documentation |
Data on Back Pain Prognosis, from Anderson (1984)
Description
Data from a study of patients suffering from back pain. Prognostic variables were recorded at presentation and progress was categorised three weeks after treatment.
Usage
data(backPain)
Format
A data frame with 101 observations on the following 4 variables.
- x2
length of previous attack.
- x3
pain change.
- x4
lordosis.
- pain
an ordered factor describing the progress of each patient with levels
worse
<same
<slight.improvement
<moderate.improvement
<marked.improvement
<complete.relief
.
Source
http://ideas.repec.org/c/boc/bocode/s419001.html
The data set and this help file was copied from gnm so that a vignette in VGAM could be run; the analysis is described in Yee (2010).
The data frame backPain2
is a modification of
backPain
where the variables have been renamed
(x1
becomes x2
,
x2
becomes x3
,
x3
becomes x4
)
and
converted into factors.
References
Anderson, J. A. (1984). Regression and Ordered Categorical Variables. J. R. Statist. Soc. B, 46(1), 1-30.
Yee, T. W. (2010). The VGAM package for categorical data analysis. Journal of Statistical Software, 32, 1–34. doi:10.18637/jss.v032.i10.
Examples
summary(backPain)
summary(backPain2)