Statistical analysis
The primary endpoint for efficacy in this study was the number
of patients achieving acomplete response afterreceiving study
medication to treat breakthrough PONV. The programmatic objective
was to identify at least one dose of vestipitant that
exceeded the complete response performance rate of ondansetron
by 20% with a posterior probability of .0.900 (calculated
to three decimal places). An interim analysis was
incorporated for the study to progress only if at least one
dose of vestipitant had a posterior probability .0.300 with its
complete response rate exceeding that of ondansetron by
20%.13 The period for the primary efficacy endpoint began 10
min after the infusion end. Complete response was defined
as no emesis and no further rescue medication from 10 min
after infusion end up to 24 h after surgery, or hospital discharge,
whichever was sooner.