baseline severity stratification
Randomization approach that ensures treatment groups are balanced across different levels of symptom severity at study entry.
Full Definition
Baseline severity stratification is a randomization strategy that divides participants into severity subgroups based on their symptom scores at study entry, then ensures balanced allocation across treatment groups within each stratum. This approach prevents chance imbalances that could confound treatment comparisons, particularly important in psychiatric trials where baseline severity strongly influences treatment outcomes. Common stratification variables include depression severity scores, psychosis severity ratings, or functional impairment levels. Stratified randomization helps ensure that treatment groups are comparable in terms of illness severity, improving the validity of between-group comparisons and potentially increasing statistical power.
Usage
Usage note: Use specific severity measures when describing stratification variables.
In Context
- "Baseline severity stratification used MADRS scores to create mild, moderate, and severe depression strata." — Randomization plan
- "The stratified analysis confirmed treatment benefits across all baseline severity levels." — Clinical study report