Group-sequential two-stage designs

Group-sequential designs are a sub-class of the TwoStageDesign class with constant stage-two sample size. See TwoStageDesign for slot details. Any group-sequential design can be converted to a fully flexible TwoStageDesign (see examples section).

GroupSequentialDesign(n1, c1f, c1e, n2_pivots, c2_pivots, order = NULL, ...)

# S4 method for GroupSequentialDesign
TwoStageDesign(n1, ...)

Arguments

n1

stage one sample size or GroupSequentialDesign object to convert (overloaded from TwoStageDesign)

c1f

early futility stopping boundary

c1e

early efficacy stopping boundary

n2_pivots

numeric of length one, stage-two sample size

c2_pivots

numeric vector, stage-two critical values on the integration pivot points

order

of the Gaussian uadrature rule to use for integration, set to length(c2_pivots) if NULL, otherwise first value of c2_pivots is repeated 'order'-times.

...

further optional arguments

See also

TwoStageDesign for superclass and inherited methods

Examples

design <- GroupSequentialDesign(25, 0, 2, 25, c(1, 1.5, 2.5))
summary(design)
#> GroupSequentialDesign: n1 =  25 
#> 
          futility |      continue     | efficacy
#> 
      x1:    -0.00 |  0.23  1.00  1.77 |  2.00
#> 
  c2(x1):     +Inf | +1.00 +1.50 +2.50 |  -Inf
#> 
  n2(x1):        0 |    25    25    25 |     0
#> 


TwoStageDesign(design)
#> TwoStageDesign<n1=25;0.0<=x1<=2.0:n2=25>