Interim Analysis — What It Means in Clinical Trials
Plain English Definition
An interim analysis is a planned review of trial data before the study is complete. An independent committee (the DSMB) examines the early results to check whether the treatment is clearly working, clearly not working, or causing safety concerns. Based on the interim analysis, the trial may continue, be modified, or be stopped early.
Why It Matters
Interim analyses protect you. If early data shows the treatment is harmful, the trial stops. If it shows the treatment is clearly better, the trial may also stop so that all participants (including the control group) can benefit.
Example
A listing might say: "Two pre-planned interim analyses will occur after 33% and 66% of events have been observed." The DSMB will review results at these checkpoints.
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