*From the Department of Preventive Medicine, University of Wisconsin Medical School, Madison, Wisconsin, and the Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota.
†From the Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, Minnesota.
‡From the Division of Health Services Research and Policy, School of Public Health, University of Minnesota, Minneapolis, Minneapolis.
Supported by a grant (RO1-HL-23727) from the National Heart, Lung, and Blood Institute.
An abstract of the preliminary findings was presented at the American Heart Association 70th Scientific Sessions, November 9-12, 1997.
Address correspondence to: Maureen A. Smith, MD, MPH, PhD, Department of Preventive Medicine, University of Wisconsin Medical School, 610 Walnut Street, Madison, Wisconsin 53705-2397.
Received December 31, 1998; initial review completed February 10, 1999; accepted June 8, 1999.
