| Value | Category |
|---|---|
| 1 | I did not use any e-cigarettes during the past 30 days |
| 2 | I bought them in a bar or tobacconist |
| 3 | I bought them in a specialized shop |
| 4 | I bought them in a pharmacy |
| 5 | I bought them in a newsstand |
| 6 | I bought them on the Internet |
| 7 | A relative/friend offered them to me |
| 8 | A stranger offered them to me |
| Sysmiss |