Framingham Heart Study is an example of :
FRAMINGHAM HEART STUDY:

Is a classical example of cohort study
Initiated in 1948 by US Public Health Service at Framingham, a town in Massachusetts, USA

Aim: To study the relationship of risk factors (serum cholesterol, blood pressure, weight,smoking) to the subsequent development of cardiovascular diseases.
Case control study
Cohort study
Cross-sectional study
Interventional study