1. Department of Medicine; University of Virginia; Charlottesville Virginia
2. Division of Epidemiology and Community Health; University of Minnesota; Minneapolis Minnesota
3. Department of Epidemiology; Rollins School of Public Health; Emory University; Atlanta Georgia
4. Department of Epidemiology; University of Washington; Seattle Washington
5. Department of Medicine; Brigham and Women's Hospital and Beth Israel Deaconess Medical Center; Harvard Medical School; Boston Massachusetts
6. Sleep Disorders Clinic; Hamilton Ontario Canada
7. Department of Epidemiology; Epidemiological Cardiology Research Center; Wake Forest School of Medicine; Winston-Salem North Carolina
8. Department of Medicine-Cardiology Section; Wake Forest School of Medicine; Winston-Salem North Carolina