3. Types of epidemiological studies

3.2 Analytic studies

Cohort study

3.2.1 Observational studies

Example of a cohort study: Framingham Heart Study

  • Early 1948: 5,209 men and women (1st generation of subjects), residents of the town of Framingham, aged 30–62 years who had not yet developed observable symptoms of cardiovascular disease or who had not suffered a heart attack or a stroke, were recruited.

  • 1971: a cohort of 2nd generation descendants (5,124 men and women, and their spouses).

  • 2003: a new cohort of 3rd generation descendants.

Initial results:

  • 1960 : smoking is associated with a risk for heart disease.

  • 1961 : High blood pressure and a high level of cholesterol is associated with a risk for heart disease.

website of the study: www.framinghamheartstudy.org