These new prospective cohort studies reflect a significant improvement over the earlier work because they include information on individual information with respect to measures related to health status and residence.
Because they don't consider health status, the new studies are worthless. 
mnli hypothesis: Because they don't consider health status, the new studies are worthless.  premise: These new prospective cohort studies reflect a significant improvement over the earlier work because they include information on individual information with respect to measures related to health status and residence.