compare | R Documentation |
Compares randomization procedures based on a specified issue in clinical trials.
compare(issue, ..., endp)
## S4 method for signature 'issue,missing'
compare(issue, ..., endp)
## S4 method for signature 'issue,endpoint'
compare(issue, ..., endp)
issue |
object of class |
... |
at least one object of class |
endp |
object of class |
Randomization procedures behave differently with respect to issues
like selection bias, chronological bias, or loss in power estimation.
The compare
function evaluates the behavior of randomization
procedures with respect to one issue.
Its first argument should represent one of the implemented
issues
.
The second argument should be any number of objects of the class
randSeq
. These objects represent the randomization procedures
for the planned comparison.
The last argument endp
may be provided if
the assessment should take the distribution of the treatment groups
into account, e.g. for power evaluation.
S4
object of class comparison
summarizing the comparison of the
randomization procedures.
Representation of randomization procedures: randPar
Generation of randomization sequences: genSeq
issues
for the assessment of randomization sequences
# compare Random Allocation Rule and Big Stick for N = 4 with respect to
# correct guesses
RAR <- getAllSeq(rarPar(4))
BSD <- getAllSeq(bsdPar(4, mti = 2))
corGuess <- corGuess("CS")
(comp <- compare(corGuess, RAR, BSD))
plot(comp)
# compare the same procedures with respect to selection bias for a normal endpoint
endp <- normEndp(c(2, 2), c(1, 1))
selBias <- selBias("CS", 4, "exact")
(comp <- compare(selBias, RAR, BSD, endp = endp))
plot(comp)
# compare the same procedures with respect to selection bias for an exponential endpoint
endp <- expEndp(lambda = c(0.5, 0.5), cenRate=0.1, accrualTime=1, cenTime=5)
selBias <- selBias("CS", 0.1, "exact")
(comp <- compare(selBias, RAR, BSD, endp = endp))
plot(comp)
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