interim analysis
Pre-planned statistical evaluation of trial data before study completion, often used for safety monitoring or efficacy assessment.
Full Definition
An interim analysis is a pre-specified evaluation of accumulating trial data conducted before the planned study completion, typically performed by an independent data monitoring committee. These analyses serve multiple purposes including safety monitoring, futility assessment, and early efficacy evaluation that may lead to trial modification or early termination. In cardiovascular research, interim analyses are particularly important for long-term outcome trials where early signals of harm or overwhelming benefit may warrant protocol changes. Editors should verify that interim analysis plans were pre-specified, that appropriate statistical adjustments for multiple testing are described, and that any protocol modifications resulting from interim analyses are clearly documented.
Usage
Usage note: Specify pre-planned nature and statistical adjustment methods. Distinguish from unplanned or post-hoc analyses.
In Context
- "The first interim analysis was planned after 50% of primary events had occurred." — Statistical analysis plan
- "Based on the interim analysis, the Data Safety Monitoring Board recommended early trial termination for efficacy." — Trial conduct report