The intention-to-treat sample, considered for efficacy and safety analysis, was composed by 374 patients, from whom 121 were assigned to pregabalin, 125 to venlafaxine XR and 128 to placebo, without significant demographic or clinical differences at baseline.
Sample size for efficacy was determined by considering the equivalence of two means based on means and standard deviations from data previously collected as part of routine quality assurance monitoring and a minimum clinically significant difference for NRS pain at discharge from PACU of 1.8.
In the aim to understand if the overall sample size analyzed for efficacy (Total N = 1,410) would be large enough to detect a potential significant valganciclovir advantage, we calculated the power needed to detect valganciclovir superiority based on a 7% reduction of CMV disease (12% to 5%), as suggested in the original trial by Paya et al. [7].
All plasma samples were centrally dosed for efficacy and safety markers (Eurofins Medinet, Plaisir, France).
The per protocol (PP) sample is defined as the group of patients that make up the ITT sample, have been assessed for efficacy and have not violated the protocol in any of the following ways: - Violation of blinding.
Even though the exclusion criteria were limited compared with those in RCTs for efficacy, the sample represents only about 30% of those assessed for eligibility which could be a source of selection bias.
For efficacy, the sample size calculation is based on non-inferiority of each of the two test dose arms to the comparator arm, the WHO-recommended dose of primaquine, 0.75 mg/kg.
It briefly describes the statistical concepts behind sample size recalculation and interim analyses for efficacy and futility, with a brief discussion on when to stop a trial.
Complex modeling may be needed to determine the effects of education and head size on disease progression, for example; such models may determine adjustments in sample size or trial duration needed for efficacy trials.
Study 2 had a smaller sample but exhibited similar temporal trends for efficacy, with significant effects in the bimatoprost group compared with the vehicle group at month 4 (the primary time point) on the end points of eyelash prominence, length, thickness, darkness, and overall satisfaction and at month 2 on the end points of satisfaction with eyelash length and fullness.
