The FHS began in 1948 and aims to identify common factors or characteristics that contribute to cardiovascular disease. The FHS has been expanded to become a multigenerational study and to include diverse populations so that risk factors in these different groups can be understood. The FHS Omni 1 was established with a new group of participants to reflect the increasing diversity of the community in Framingham, Massachusetts, United States of America. Participants are over 500 men and women of African American, Hispanic, Asian, Indian, Pacific Islander and Native American origins, who were residents of Framingham and the surrounding towns. Baseline assessment was conducted from 1994 to 1998, and participants have since undergone assessment every few years. The Omni 1 cohort has been examined in five cycles, the latest completed in 2022. A subset of participants in the FHS Omni 1 cohort also participated in the eFHS sub-study.