Overview of CHS Design

CHS is a prospective population-based cohort study of risk factors for CHD and stroke in adults 65 years and older. In June 1990, four Field Centers completed the recruitment of 5201 participants. Between November 1992 and June 1993, an additional 687 African Americans were recruited using similar methods. The Field Centers are located in Forsyth County, NC; Sacramento County, CA; Washington County, MD; and Pittsburgh, PA. The baseline examinations consisted of a home interview and a clinic examination that assessed not only traditional risk factors but also measures of subclinical disease, including carotid ultrasound, echocardiography, electrocardiography, and pulmonary function.

Follow-up of the cohort

Until 1999, semi-annual contacts alternated between clinic examinations and telephone contacts, during which information about hospitalizations and potential cardiovascular events was collected. Standard protocols for the identification and adjudication of events were implemented during follow-up. The adjudicated events are CHD, angina, heart failure (HF), stroke, transient ischemic attack (TIA), claudication, and mortality.

Major exam components were repeated during annual follow-up examinations through 1999. Cranial MRI scans, retinal photography, and tests of endothelial function were added as new components. Details of study exam components can be found at Study Component Schedules.

Since 1999, participants have been contacted twice a year by telephone to collect limited data, including medication data, and to identify all hospitalizations and potential cardiovascular events. CHS currently plans to follow participants for events that occur through 2006. Participants have also been invited to participate in a clinic or home visit as part of the CHS All Stars Study which begins the seventeenth year of data collection and includes follow-up for events. The six-month contact of this current data collection cycle is also underway.

Papers using CHS data

To date, more than 1,000 research papers from CHS have been published (see Published Papers) and many more are in progress. CHS has made important contributions to medical knowledge. New manuscript proposals are welcome. Please see our Data Distribution Policy.

Ancillary studies to CHS

Ancillary studies have used CHS data and stored biological specimens (CHS Lab Information) to answer new questions at a small marginal cost. More than 200 ancillary studies are ongoing or complete and several more have been approved in CHS. New ancillary study proposals are welcome.

For researchers interested in learning more about CHS: See New Investigator Info.