Table 1 Categorisation and characteristics of subjects
Group 1 | Group 2 | Group 3 | |
|---|---|---|---|
Questionnaire(s) answered | 1999 only | 2001 only | 1999 and 2001 |
Number of individuals | 930 | 1000 | 1558 |
Age 16–24 | 34.2% | 41.2% | 21.1% |
Age 25–34 | 35.8% | 31.5% | 34.1% |
Age 35–44 | 30.0% | 27.3% | 44.9% |
Female | 53.2% | 51.8% | 56.3% |
Never smokers | 40.0% | 39.1% | 47.2% |
ETS exposure | 53.8% | 52.7% | 46.0% |