What is a prespecified interim analysis?
When planning a group sequential trial, investigators must prespecify plans for interim analyses. This generally includes when the interim analyses will occur, what information will be used, and what statistical methods and stopping criteria will be applied.
What is the O’Brien-Fleming approach?
O′Brien-Fleming bounds use more conservative stopping boundaries at early stages. These bounds spend little alpha at the time of the interim looks and lead to boundary values at the final stage that are close to those from the fixed sample design, avoiding the problem with the Pocock bounds.
What is interim futility analysis?
The interim analysis for futility: To see if the new treatment is unlikely to beat the control – then stop the trial for futility – this is called ‘futility analysis’.
What is O’Brien-Fleming spending function?
Alpha spending functions that approximate O’Brien-Fleming or Pocock Boundaries are as follows: O ‘ Brien – Fleming : α 1 ( t ∗ ) = 2 – 2 Φ ( Z α / 2 / t ∗ ) , Pocock : α 2 ( t ∗ ) = α ln ( 1 + ( e – 1 ) t ∗ ) , where Φ denotes the standard normal cumulative distribution function.
What is the importance of interim analysis?
An interim analysis compares randomised arms at any time point before the end of a phase 3 trial and usually occurs before recruitment is complete. It is especially appealing to the regulatory agencies and the sponsor, allowing for decisions and changes to be made in the middle of the study.
Why is interim analysis conducted?
Interim analyses can be conducted as part of an adaptive trial design to formally monitor the accumulating data in clinical trials. They are generally performed in trials that have a DMC, longer duration of recruitment, and potentially serious outcomes.
What is interim analysis RCT?
In clinical trials and other scientific studies, an interim analysis is an analysis of data that is conducted before data collection has been completed. Clinical trials are unusual in that enrollment of subjects is a continual process staggered in time.
What is interim data?
Scientific information that is studied part way through a medical research project to see whether there are hazards associated with the study or clear benefits from one treatment or another.
Why do an interim analysis in a clinical trial?
What is first interim analysis?
What are two reasons to include an interim analysis in a clinical trial?
What is an interim analysis and why is it important?
- An opportunity to re-estimate the sample size.
- An opportunity to modify the trial design.
- An option to stop the trial for efficacy or futility.
- An option to continue the trial as originally planned.
Who conducts the interim analysis?
An interim-analysis is performed on the primary endpoint when 50% of patients have been randomised and have completed the 6 months follow-up. The interim-analysis is performed by an independent statistician, blinded for the treatment allocation.