| Value | Category |
|---|---|
| 1 | I have never smoked cigarettes |
| 2 | I no longer smoke cigarettes |
| 3 | No, I smoke cigarettes but I have never mixed them with other drugs |
| 4 | Yes, I have mixed but only once or twice |
| 5 | Yes, I have mixed cigarettes with other drugs more than twice |
| Sysmiss |