stop_for_excess_toxicity_empiric: Stopping for excess toxicity - Empiric method
In dtpcrm: Dose Transition Pathways for Continual Reassessment Method

Description Usage Arguments Details Examples

This is a function for use with applied_crm for the stop_func argument. The rule will suggest stopping in the scenario that the probability of toxicity being greater than a specifed value at a defined dose is greater than some further specified certainty value.

1 2	stop_for_excess_toxicity_empiric(x, tox_lim, prob_cert, dose = 1, nsamps = 10^6, suppress_dose = TRUE)

`x`	An object of class 'mtd'.
`tox_lim`	A numeric; specifying the value for which the estimated toxicity at the selcted dose is not to exceed.
`prob_cert`	A numeric; specifying the probability value to be used when assessing the certainty required that toxicty at the specificed dose exceeds tox_lim.
`dose`	An integer; the dose to be assessed.
`nsamps`	number of samples used for beta in the underlying normal sampling of beta.
`suppress_dose`	A logical value indicating if the MTD should be set to NA if trial should stop.

This function is an example of a possible stopping function to be used with applied_crm, it will modifiy the 'mtd' class object produced by applied_crm to include a logical value under the name 'stop' indicating whether or not the trial should stop. The package dtpcrm contains a few of these functions for possible use with applied_crm.

prior  <- c(0.1, 0.3, 0.5)
target <- 0.2
tox    <- c(0, 0, 1, 0, 1, 1)
level  <- c(1, 1, 1, 2, 2, 2)

stop_rule <- function(x){
  x <- stop_for_excess_toxicity_empiric(x, tox_lim = 0.25, prob_cert = 0.85)
}

crm <- applied_crm(prior, target, tox, level, no_skip_esc = TRUE, no_skip_deesc = TRUE,
                   global_coherent_esc = TRUE, stop_func = stop_rule)