What is Stratification?

Stratification is the process of grouping clinical trial participants based on predefined characteristics before randomization or analysis. Factors such as age, disease severity, sex, or geographic region may be used to create strata, helping ensure these characteristics are balanced across treatment groups.

Stratification is commonly used in clinical trials to reduce potential bias and improve comparability between treatment groups. Balancing important participant characteristics across study arms, it helps ensure that differences in trial outcomes are more likely to reflect the treatment being studied rather than underlying population differences.

Stratification factors are defined in the study protocol and are typically incorporated into the study's randomization strategy before participant enrollment begins.

During study setup, study teams can configure protocol-defined stratification factors, participant allocation rules, and randomization schedules within Clinion RTSM. Factors such as age, disease severity, geographic region, or prior treatment history can be incorporated into the randomization strategy to support balanced participant allocation.

As participants are enrolled, Clinion RTSM automatically applies the configured stratification rules to assign participants to the appropriate study arm according to the predefined randomization schedule. This helps maintain balanced treatment groups, reduces manual intervention, and supports consistent protocol execution across study sites.

A clinical trial may stratify participants based on disease severity before randomization. Participants with mild disease are grouped into one stratum, while those with moderate disease are grouped into another. Within each stratum, participants are then randomly assigned to the treatment or control group to help maintain balanced study populations.

Randomization

Stratification Factor

Study Arm

Cohort

Clinical Trial Protocol

Subject Enrollment

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