1. Biostatistics Section, Division of Scientific Data Registry, Atomic Bomb Disease Institute, Nagasaki University, 12-4 Sakamoto 1-chome, Nagasaki 852-8523, Nagasaki, Japan
2. Department of Radiation Biology and Protection, Atomic Bomb Disease Institute, Nagasaki University, 12-4 Sakamoto 1-chome, Nagasaki 852-8523, Japan
3. Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University, 12-4 Sakamoto 1-chome, Nagasaki 852-8523, Japan
4. Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University, 12-4 Sakamoto 1-chome, Nagasaki 852-8523, Japan