Toshimitsu Hamasaki, Professor, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
Koko Asakura, Research Assistant, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
Scott Richard Evans, Senior Research Scientist, Harvard School of Public Health, 651 Huntington Avenue, Boston, Massachusetts 02115, USA
Toshimitsu Ochiai, Biostatistics Department, Shionogi & Co., Ltd., Japan
