Table 1 Baseline characteristics of the participants
| Â | Total | Non-smokers* | Passive smokers** | P-value | |||
|---|---|---|---|---|---|---|---|
| Â | n | (%) | n | (%) | n | (%) | Â |
Age | Â | Â | Â | Â | Â | Â | Â |
   <50 years old | 367 | (53%) | 225 | (50%) | 142 | (59%) | 0.036 |
   ≥50 years old | 322 | (47%) | 222 | (50%) | 100 | (41%) |  |
Sex | Â | Â | Â | Â | Â | Â | Â |
   Male | 257 | (37%) | 159 | (36%) | 98 | (40%) | 0.137 |
   Female | 432 | (63%) | 288 | (64%) | 144 | (60%) |  |
Managerial position | Â | Â | Â | Â | Â | Â | Â |
   General teacher | 572 | (83%) | 373 | (83%) | 199 | (82%) | 0.269 |
   Principal or vice-principal | 60 | (9%) | 42 | (9%) | 18 | (7%) |  |
   School nurse or dietitian | 57 | (8%) | 32 | (7%) | 25 | (10%) |  |
School type | Â | Â | Â | Â | Â | Â | Â |
   Elementary school | 437 | (63%) | 300 | (67%) | 137 | (57%) | 0.001 |
   Junior high school | 221 | (32%) | 135 | (30%) | 86 | (36%) |  |
   High school | 31 | (4%) | 12 | (3%) | 19 | (8%) |  |
Attitude towards smoke-free schools | Â | Â | Â | Â | Â | Â | Â |
   Positive | 555 | (81%) | 357 | (80%) | 198 | (82%) | 0.537 |
   Not positive | 134 | (19%) | 90 | (20%) | 44 | (18%) |  |
Total | 689 | 447 | 242 | Â | |||