Table 1.
Descriptive sample statistics at baseline and attrition analysis
| Baseline never-smokers |
Lost to follow-up |
Analyzed Sample |
p-value | |
|---|---|---|---|---|
| (n=11691) | (n=1704) | (n=9987) | ||
| % | % | % | ||
| Country | ||||
| Germany | 17.2 | 15.7 | 17.4 | <0.001 |
| Iceland | 20.6 | 23.9 | 20.1 | |
| Italy | 13.8 | 8.8 | 14.7 | |
| The Netherlands | 8.3 | 6.7 | 8.6 | |
| Poland | 20.3 | 28.3 | 18.9 | |
| United Kingdom | 19.8 | 16.6 | 20.3 | |
| SOCIODEMOGRAPHICS | ||||
| Age at baseline, M(SD) | 13.19 (1.11) | 13.44 | 13.15 (1.10) | <0.001 |
| Gender | ||||
| Female | 50.7 | 47.2 | 51.3 | 0.002 |
| Male | 49.3 | 52.8 | 48.7 | |
| Family Affluence | ||||
| Low | 8.3 | 10.7 | 7.9 | 0.001 |
| Medium | 35.5 | 34.7 | 35.7 | |
| High | 56.2 | 54.6 | 56.4 | |
| PERSONAL CHARACTERISTICS | ||||
| School performance | ||||
| Below average | 4.3 | 7.2 | 3.8 | <0.001 |
| Average | 29.2 | 31.8 | 28.8 | |
| Good | 46.0 | 42.0 | 46.6 | |
| Excellent | 20.5 | 19.1 | 20.8 | |
| TV screen time per day, hours, M (SD) | 1.77 (1.18) | 1.79 (1.24) | 1.76 (1.17) | 0.420 |
| Sensation-seeking and rebelliousness, M(SD), range: 0–4 | 1.12 (0.66) | 1.21 (0.72) | 1.10 (0.65) | <0.001 |
| SOCIAL ENVIRONMENT | ||||
| Peer smoking | ||||
| None | 54.5 | 47.9 | 55.7 | <0.001 |
| A few | 27.1 | 29.2 | 26.8 | |
| Some | 13.2 | 15.1 | 12.9 | |
| Most/all | 5.1 | 7.9 | 4.6 | |
| Mother figure smoking | ||||
| No | 77.6 | 73.3 | 78.3 | <0.001 |
| Yes | 22.4 | 26.7 | 21.7 | |
| Father figure smoking | ||||
| No | 71.4 | 67.7 | 72.1 | <0.001 |
| Yes | 28.6 | 32.3 | 27.9 | |
| Any sibling smoking | ||||
| No | 87.8 | 83.4 | 88.6 | <0.001 |
| Yes | 12.2 | 16.6 | 11.5 |