Question

A cohort study is assessing the association of red meat consumption with cardiovascular disease. From external knowledge, we know that red meat intake and CVD are correlated with diet (e.g., high intake of refined sugars, low intake of fruits) and behavior (e.g., low physical activity). Draw the DAG for this study and include at least one of the correlated behavioral or dietary factors. Describe the bias that is most likely generated in this study.

Answer 1

The most likely bias could be selection bias as they may choose men who have these behaviors of eating more fatty foods other then red meat and those men may also do less physical activity. They may use this to their favor about the correlation between CVD and red meat intake.

Since high sugar diets and low physical activity are common causes of cardiovascular disease, this form of bias would be a confounder. Confounds are one common biases in cohort studies.

Diagram :