Treatment of Middle East Respiratory Syndrome with a combination of lopinavir-ritonavir and interferon-β1b (MIRACLE trial): study protocol for a randomized controlled trial

Table 2 Stopping boundaries

Boundary	Value	Comment
Efficacy stopping boundary (α₁₁)	0	No stopping for efficacy
Efficacy stopping boundary (β₁₁)	0.2	Stop the trial for futility if less than stage-wise p value
Efficacy stopping boundary (α₁₂)	0.2250	Stop trial for efficacy at the second stage or recalculate based on conditional power at first interim analysis

ISSN: 1745-6215