| Value | Category |
|---|---|
| 1 | I have not used an electronic cigarette during the past 30 days |
| 2 | I bought it on the Internet |
| 3 | I bought it at a sales point |
| 4 | I received it as a gift |
| 5 | A friend gave it to me |
| 6 | Parents gave it to me |
| 7 | I obtained it in another way |
| Sysmiss |