86
Evaluating Boundaries
Stopping boundary at each analysis
–On the scale of estimated treatment effect
•Inform
DMC of precision
•Assess
ethics
»May
have prior belief of unacceptable levels
•Assess
clinical, economic importance
–On the Z, fixed sample P value, or error spending
scales
(DMC)
(Clinicians,Marketing)
(DMC, Statisticians)
(Often asked for, but of questionable relevance)