The study design permits many types of analyses to be performed within a single dataset. The analyses address a wide range of issues related to the causes and consequences of common age related conditions, while controlling for demographics and other potential confounding variables. Analyses without neuropathologic indices are performed in the entire cohort. Thus, the temporal relation between a risk factor and clinical outcome is established in the entire cohort. This allows us to draw valid inferences from the cross-sectional associations with pathology.
