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\name{psor}
\alias{psor}
\title{Psoriatic arthritis data}
\description{
A series of observations of grades of psoriatic arthritis, as
indicated by numbers of damaged joints.
}
\usage{data(psor)}
\format{
A data frame containing 806 observations, representing visits to a
psoriatic arthritis (PsA) clinic from 305 patients. The rows
are grouped by patient number and ordered by examination time. Each
row represents an examination and contains additional covariates.
\tabular{rll}{
\code{ptnum} \tab (numeric) \tab Patient identification number \cr
\code{months} \tab (numeric) \tab Examination time in months \cr
\code{state} \tab (numeric) \tab Clinical state of PsA. Patients in
states 1, 2, 3 and 4 \cr \tab \tab have 0, 1 to 4, 5 to 9 and 10 or more damaged
joints, \cr \tab \tab respectively. \cr
\code{hieffusn} \tab (numeric) \tab Presence of five or more effusions \cr
\code{ollwsdrt} \tab (character) \tab Erythrocyte sedimentation rate of
less than 15 mm/h \cr
}}
\references{
Gladman, D. D. and Farewell, V.T. (1999) Progression in psoriatic arthritis:
role of time-varying clinical indicators. J. Rheumatol. 26(11):2409-13
}
\examples{
## Four-state progression-only model with high effusion and low
## sedimentation rate as covariates on the progression rates. High
## effusion is assumed to have the same effect on the 1-2, 2-3, and 3-4
## progression rates, while low sedimentation rate has the same effect
## on the 1-2 and 2-3 intensities, but a different effect on the 3-4.
data(psor)
psor.q <- rbind(c(0,0.1,0,0),c(0,0,0.1,0),c(0,0,0,0.1),c(0,0,0,0))
psor.msm <- msm(state ~ months, subject=ptnum, data=psor,
qmatrix = psor.q, covariates = ~ollwsdrt+hieffusn,
constraint = list(hieffusn=c(1,1,1),ollwsdrt=c(1,1,2)),
fixedpars=FALSE, control = list(REPORT=1,trace=2), method="BFGS")
qmatrix.msm(psor.msm)
sojourn.msm(psor.msm)
hazard.msm(psor.msm)
}
\keyword{datasets}
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