The Framingham Study

One of the best-known examples of a cohort study is the Framingham Study, which was carried out in Framingham, Massachusetts.¹⁹ Framingham was selected because of the size of the population, the relative ease with which the people could be contacted, and the stability of the popu­lation in terms of moving into and out of the area. This longitudinal study, which began in 1950, was set up by the U.S. Public Health Service to study the characteristics of people who would later develop coronary heart disease. The study consisted of 5000 persons, aged 30 to 59 years, selected at random and followed for an initial period of 20 years, during which time it was predicted that 1500 of them would develop coronary heart disease. The advan­tage of such a study is that it can study a number of risk factors at the same time and determine the relative im­portance of each. Another advantage is that the risk fac­tors can be related later to other diseases such as stroke. Chart 1-1 describes some of the significant milestones from the Framingham Study.