Confounding in a DAG is illustrated when a variable is caused by the exposure, and it causes the outcome.
Understand the Problem
The question is addressing the concept of confounding in a Directed Acyclic Graph (DAG) where a variable is both affected by the exposure and influences the outcome. This implies a need to understand causal relationships within a DAG framework.
Answer
The statement describes mediation, not confounding.
The statement describes mediation, not confounding, because the variable is both caused by the exposure and causes the outcome.
Answer for screen readers
The statement describes mediation, not confounding, because the variable is both caused by the exposure and causes the outcome.
More Information
In causal diagrams, a confounder is usually a variable that influences both the exposure and the outcome independently. Mediation involves a variable lying on the causal path between exposure and outcome.
Tips
A common mistake is confusing a mediator with a confounder in causal diagrams. Identify if a variable is merely on the path or independently affects both variables.
Sources
- Directed acyclic graphs: a tool for causal studies in paediatrics - nature.com
- Confounding and Effect Measure Modification - sph.bu.edu - sphweb.bumc.bu.edu
