Table 1.
Annual smoking frequency of students and percentage of new starters.
| Prevalence | Incidence* | |||||
| Years | n | Smokers | % (%95 CI) | n | New smokers | % (%95 CI) |
| 1st (register) | 119 | 26 | 21.8 (15.3–30.1) | - | - | - |
| 2nd | 119 | 35 | 29.9 (21.9–38.2) | 93 | 12 | 12.9 (7.5–21.2) |
| 3rd | 119 | 38 | 31.9 (24.2–40.8) | 81 | 6 | 7.4 (3.5–15.2) |
| 4th | 119 | 40 | 33.6 (24.2–40.8) | 75 | 7 | 9.3 (4.6–18.1) |
| 5th | 112 | 29 | 25.9 (18.7–34.7) | 68 | 2 | 2.9 (1.0–10.1) |
| 6th | 115 | 31 | 27.0 (19.7–35–7) | 66 | 3 | 4.5 (1.6–12.5) |
*: For incidence calculations, only the new smokers within a particular year were taken into account; e.g. a group of students who smoked in the first year (21.8%) was not included in the calculations for the second year (29.9%).