sample size adjustment

sample size adjustment

In a clinical trial, an interim assessment of blinded data to validate sample size calculations or reevaluate the sample size.
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The purpose of the interim analysis was to allow for a sample size adjustment if necessary to maintain appropriate statistical power to detect a treatment effect between Clonidine Topical Gel and placebo.
This study, known by the acronym VALOR, has an innovative, adaptive design that allows for a one-time sample size adjustment based on the outcome of an interim analysis, due in mid-2012.
As a result of the interim analyses, it was determined that no sample size adjustment will be necessary to the opioid naive study.
The VALOR trial employs an innovative, adaptive trial design that allows for a one-time sample size adjustment by the DSMB at the interim analysis to maintain adequate power across a broad range of clinically meaningful and statistically significant survival outcomes.
Following review of the currently available data, the committee concluded that a sample size adjustment would not be required and unanimously voted that the study can continue to completion.
Design information-based trials allowing sample size adjustments at interim looks - Design non-inferiority trials powered for superiority alternatives - Calculate sample size and stopping boundaries for superiority, futility, non-inferiority and equivalence studies - Choose symmetric, asymmetric, and futility stopping boundaries from the Wang-Tsiatis, Lan-DeMets, and Haybittle-Peto families; specify stopping boundaries from a number of published error-spending functions, or specify your own spending functions - Examine design properties with interactive repeated confidence intervals - Compare different trial designs side by side