Treatment Contrast Interaction

**Semantic type:** Conceptual Entity

**Definition:** The situation in which a treatment contrast (e.g., difference between investigational product and control) is dependent on another factor (e.g., center). A quantitative interaction refers to the case where the magnitude of the contrast differs at the different levels of the factor, whereas for a qualitative interaction, the direction of the contrast differs for at least one level of the factor. (ICH)

**Synonyms:** - interaction (qualitative and quantitative) - treatment contrast interaction