| Project stratification | Tongxinluo group (case) | Control group (case) |
| male/female (case) | 8/20 | 8/20 |
| age < 55 | 8 | 10 |
| 55 < age < 70 | 20 | 18 |
| farmer | 3 | 2 |
| worker | 12 | 15 |
| Professional and technical personnel | 13 | 11 |
| Degree of education: primary school | 3 | 4 |
| Middle school | 7 | 9 |
| Higher school | 15 | 13 |
| University and above | 3 | 2 |