| Value | Category |
|---|---|
| -9 | REFUSED |
| -7 | DO NOT KNOW |
| 1 | SUBMITTED ONESELF TO TREATMENT |
| 2 | STOPPED SMOKING ALL OF A SUDDEN |
| 3 | GRADUALLY DECREASED THE NUMBER OF CIGARETTES |
| 4 | STOPPED PURCHASING CIGARETTES |
| 5 | SUBSTITUTED SMOKING WITH ANOTHER ACTIVITY |
| 6 | OTHER REASON |
| Sysmiss |