Bias in Environmental Cohort Studies.

The article presents the study that examines bias in the use of data on lead exposure and mortality in men and directed acyclic graphs (DAGs). This study was participated by 835 white male, average age of 67 years old, who were part of the Normative Aging Study (NAS). The relationship between patella lead and mortality from cardiovascular disease and from ischemic heart disease. The study found that those with higher patella lead levels have higher risk of dying from ischemic heart disease.