| Smoking | Number | % |
| Never smoked | 198 | 52.5 |
| One to two years ago | 6 | 1.6 |
| Four to twelve months ago | 3 | 0.8 |
| One to three months ago | 2 | 0.5 |
| Within the last month | 24 | 6.4 |
| Missing | 144 | 38.2 |
| Total | 377 | 100.0 |