Upper stopping boundaries
=========================

For a multi-stage group-sequential design, **multiarm** requires a
choice about the type of upper (efficacy) stopping boundary to use. This
can be either fixed (a common interim value), O’Brien Fleming, Pocock,
or triangular. Specify your chosen type of upper stopping boundary here.
If fixed is chosen, an input box will appear for you to specify the
common fixed interim stopping boundary.
