*! version 1.0 16 Apr 2015

Title

triangular -- Triangular Test

Syntax

triangular
[,
options]

Main
l(integer 3) The maximum number of allowed stages in the design. Must be an integer greater than or equal to 2.

delta(real 0.2) The clinically relevant difference at which to power. Must be strictly positive.

alpha(real 0.05) The desired type-I error rate. Must be strictly between 0 and 1.

beta(real 0.2) The desired type-II error rate. Must be strictly between 0 and 1.

sigma(numlist) The standard deviation of the responses in the two arms. This can either be of length two, containing the assumed values of these responses, or of length one, implying the standard deviation in each arm is equal. All values must be strictly positive.

ratio(real 1) The desired ratio of the sample sizes between the two arms. Must be strictly positive.

performance Specifies that the performance of the identified design, i.e. its expected sample size and power curves, should be determined and plotted.

* Additional options to pass to twoway.

Description

triangular determines the boundaries of, and sample size required by, a triangular test.

Options

Main

l(integer 3) The maximum number of allowed stages in the design. Must be an integer greater than or equal to 2.

delta(real 0.2) The maximum number of allowed stages in the design. Must be an integer greater than or equal to 2.

alpha(real 0.05) The desired type-I error rate. Must be strictly between 0 and 1.

beta(real 0.2) The desired type-II error rate. Must be strictly between 0 and 1.

sigma(numlist) The standard deviation of the responses in the two arms. This can either be of length two, containing the assumed values of these responses, or of length one, implying the standard deviation in each arm is equal. All values must be strictly positive.

ratio(real 1) The desired ratio of the sample sizes between the two arms. Must be strictly positive.

performance Specifies that the performance of the identified design, i.e. its expected sample size and power curves, should be determined and plotted.

* Additional options to pass to twoway.

Examples

triangular, sigma(1)

triangular, l(2) delta(0.25) alpha(0.1) beta(0.1) sigma(2, 3) ratio(2) per

Authors

Michael J. Grayling & Adrian P. Mander,
MRC Biostatistics Unit, Cambridge, UK.

Email mjg211@cam.ac.uk

See Also

References:

Whitehead J, Stratton I (1983) Group Sequential Clinical Trials with
Triangular Continuation Regions. Biometrics 39(1):227-236.

Related commands:

doubleTriangular (if installed)
haybittlePeto (if installed)
innerWedge (if installed)
powerFamily (if installed)
wangTsiatis (if installed)