From the Welch Center for Prevention, Epidemiology, and Clinical Research (J.H., M.J.K., P.K.W.), the Department of Epidemiology (J.H., M.J.K., P.K.W.), the Department of Medicine (M.J.K., P.K.W.), and the Department of Health Policy and Management (M.J.K.), The Johns Hopkins University School of Hygiene and Public Health and School of Medicine, Baltimore, Md, and the Department of Epidemiology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, People’s Republic of China... (At 1995-12)