Episode

Adaptive Subgroup Selection in Sequential Trials

with Balasubramanian Narasimhan

useR! International R User 2017 Conference

useR!2017: Adaptive Subgroup Selection in Sequentia...

[`ASSISTant`](https://cran.r-project.org/package=ASSISTant) is an R
package for a novel group-sequential adaptive trial. The design is
motivated by a randomized controlled trial to compare an endovascular
procedure with conventional medical treatment for stroke patients; see
Lai, Lavori and Liao [-@Lai2014191]. The endovascular procedure may
be effective only in a subgroup of patients not known at the design
stage but may be learned statistically from the data collected during
the course of the trial. The group-sequential design implemented in
`ASSISTant` incorporates adaptive choice of the patient subgroup among
several possibilities which includes the entire patient population as
a choice. Appropriate Type I and type II errors of a test can be
defined in this setting and the design maintains a prescribed type I
error by using the closed testing principle in multiple testing.

This adaptive design underlies the
[NIH DIFFUSE-3](https://www.nihstrokenet.org/clinical-trials/acute-interventional-trials/defuse-3)
trial currently underway. The package is on CRAN [-@assistant] and
github.