pselect {clinfun}R Documentation

Probability of selection under pick the winner rule

Description

Calculates the probability of selecting the treatment with the higher response rate under the pick the winner rule.

Usage

pselect(n, p, min.diff=1, min.resp=0)

Arguments

n sample size for each treatment arm.
p vector of response rates for the treatments.
min.diff the minimum number by which the number of responses should exceed for the treatment arm to be chosen. This must be a positive integer (default=1).
min.resp the minimum number of responses in each treatment arm for it to be considered further (default=0).

Value

the function returns a list with:

prob.none.selected is the probability that no treatment has at least min.resp responses. this element is present only if min.resp is greater than 0.
prob.not.unique this is the probability that the best treatment has min.resp responses but exceeds the second best by less than min.diff responses.
prob.selection this is a matrix which for each treatment gives the response probability and the probability of selecting it i.e. the number of responses in the chosen arm is at least min.resp and exceeds that in the remaining arms by at least min.diff.

References

Simon R, Wittes RE, Ellenberg SS. (1985). Randomized phase II clinical trials. Cancer Treat Rep 69, 1375-1381.

Examples

  pselect(18, c(0.2, 0.2, 0.2)) # selection when no diffrence i.e. type I error
  pselect(18, c(0.2, 0.2, 0.4)) # selection probability
  pselect(26, c(0.2, 0.2, 0.4), min.diff=2, min.resp=3)

[Package clinfun version 0.7-4 Index]