BACKGROUND:
Over the last forty years, epidemiologic studies have made basic contributions to knowledge of the etiology and natural history of the chronic diseases -- cardiovascular diseases, diabetes, and cancers. Findings from the epidemiologic studies have provided practical foundations for the development of prevention and control programs to improve life styles and to control high blood pressure by drugs, when indicated. These developments and their impact on life styles and risk factors have probably contributed to the marked decline in mortality rates from coronary heart disease, stroke, all cardiovascular disease, and all causes throughout the 1970s and 1980s.
The four epidemiologic studies have as their foundation the major contributions of the earlier 'first generation' epidemiological studies including the Albany Civil Servant Study, the Charleston Study, the Framingham Heart Study, the Tecumseh Study and others. The significance of these studies lies in their potential for elucidating key 'second generation' issues in the epidemiology of the major cardiovascular and non-cardiovascular chronic diseases.
DESIGN NARRATIVE:
Chicago Heart Association Detection Project in Industry: Employees of 85 firms in the greater Chicago area were screened between the Fall of 1967 to early 1973. The total labor force among these companies was over 75,000 persons. The volunteer rate for the screening was 55 percent. All employees were encouraged to participate irrespective of job type or shift worked. At each employment site data were collected on smoking habits, previous medical diagnosis, current treatments for hypertension, heart disease and diabetes, height and weight, age, sex, race, heart rate.
Peoples Gas Company: All data on the two cohorts were collected as part of the periodic medical examination program for all employees in the Medical Department of the Company by its full-time staff of physicians. Data were collected on age, race, height, weight, blood pressure, serum cholesterol, smoking history, heart rate, resting ECG, medical and family history, alcohol and coffee and tea consumption, education, military service, occupation, physical activity, diet, and glucose and serum uric acid levels. Repeat exams were scheduled yearly for men 50-59, every two years for men 40-49, and every four years for men 25-39.
Western Electric Company: This longitudinal study of coronary heart disease was initiated in 1957 at the Hawthorne Works of the Western Electric Company in Chicago. The male subjects were free of coronary heart disease at baseline. The medical history and physical examination were modeled after the Framingham Heart Study. Data were collected on diet, physical activity, electrocardiogram, blood hemoglobin and blood cholesterol levels, body fatness, blood pressure, height, weight, lipoprotein lipase, glucose level, and smoking.
The study was renewed in FY 1992 and again in FY 1998. The 1998 renewal used data and analyses from the four cohorts. It focused on six specific aims: factors influencing coronary heart disease-cardiovascular disease risk long-term in young adult women and men (ages 18 to 39 at baseline); factors influencing coronary heart disease-cardiovascular disease risk long-term in African-American women and men; factors influencing coronary heart disease-cardiovascular disease risk during both earlier and later follow-up (first 15 years and beyond 15 years of follow-up); impact of baseline low risk status on long-term risk of mortality from coronary heart disease, cardiovascular disease, non-cardiovascular disease, and all causes; relationship of habitual intake of multiple food groups to 10 year change in serum cholesterol, blood pressure, weight, and to 30-year risks of death from coronary heart disease, cardiovascular disease, cancers, and all causes; differences in risk factors impact between groups based on sex, race, age, or risk factor status.
The study has been extended through July 2005 and uses data and analyses from the Chicago Heart Association Detection Project in Industry cohort. The study focuses on three specific aims: factors influencing coronary heart disease and cardiovascular disease risk long-term in young adult women (ages 18-39 at baseline); factors influencing coronary heart disease and cardiovascular disease risk long-term in young adult and middle-aged African American men and women; and the impact of baseline "low risk" status on long-term mortality from coronary heart disease, cardiovascular disease, non-cardiovascular disease, and all causes in young adult women (ages 18-39), including African-American and white women.
