Percentage of self reported non-smokers (had not smoked in the past month) having serum cotinine higher than 10 ng/ml by sociodemographic groups
| *χ2 test between the groups. | ||
| Sex | NS* | |
| Men | 4.6 | |
| Women | 3.4 | |
| Age | NS | |
| 25–34 | 3.2 | |
| 35–44 | 4.3 | |
| 45–54 | 3.4 | |
| 55–64 | 4.5 | |
| Area | NS | |
| North Karelia | 4.1 | |
| Kuopio province | 3.3 | |
| South western Finland | 4.2 | |
| Helsinki capital area | 4.0 | |
| Marital status | NS | |
| Married | 3.8 | |
| Single | 3.5 | |
| Divorced | 5.1 | |
| Widow | 4.1 | |
| Education | NS | |
| Basic education | 3.9 | |
| Vocational school | 3.7 | |
| Medium level | 4.0 | |
| Academic level | 3.9 | |