Table 1. Characteristics and the number of study participants of each hospital.
| Hospital | Characteristic | Number of study participants |
| Special wards of Tokyo | 15,324 | |
| Tokyo Metropolitan Matsuzawa Hospital | A center for psychiatric care in Tokyo | 2,180 |
| Toshima Hospital | Core hospital in northwest part of special wards | 2,516 |
| Ohkubo Hospital | Core hospital in western part of special wards | 993 |
| Tokyo Metropolitan Hiroo Hospital | An emergency and disaster medical center | 1,260 |
| Ebara Hospital | Core hospital in southern part of special wards | 910 |
| Tokyo Metropolitan Ohtsuka Hospital | A center for perinatal and pediatric care in Tokyo | 1,620 |
| Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital | A center for cancer and infectious disease care in Tokyo | 1,965 |
| Tokyo Metropolitan Bokutoh Hospital | A comprehensive hospital in eastern Tokyo | 2,200 |
| Tobu Chiiki Hospital | A core hospital in the eastern part of Tokyo | 1,680 |
| Tama area | 7,910 | |
| Tama-Hokubu Medical Center | Core hospital in the North Tama area | 3,078 |
| Tokyo Metropolitan Children’s Medical Center | A center for pediatric care in Tokyo | 535 |
| Tokyo Metropolitan Tama Medical Center | Core hospital in the Tama area | 2,080 |
| Tokyo Metropolitan Neurological Hospital | A center of the treatment of intractable neurological diseases | 377 |
| Tama-Nambu Chiiki Hospital | Core hospital in the South Tama area | 1,840 |