Parental smoking history
| Father, n (%) | Mother, n (%) | |
|---|---|---|
| Cigarette smoking | ||
| Never | 816 (62.4) | 1298 (98.0) |
| Current | 349 (26.7) | 17 (1.3) |
| Former | 142 (10.9) | 9 (0.7) |
| Cigarette smoking during child’s lifetime | ||
| No | 871 (66.7) | 1301 (98.3) |
| Yes | 434 (33.3) | 23 (1.7) |
| Current smokers: | ||
| Number of cigarettes smoked per day | ||
| 0 | 843 (63.2) | 1308 (98.1) |
| 6 or less | 177 (13.3) | 15 (1.1) |
| 7–12 | 161 (12.1) | 6 (0.5) |
| 13–22 | 115 (8.6) | 4 (0.3) |
| 23–32 | 27 (2.0) | 1 (0.1) |
| 33–42 | 8 (0.6) | 0 (0.0) |
| 43 or more | 3 (0.2) | 0 (0.0) |
| Number of cigarettes smoked per day during child’s lifetime | ||
| 0 | 871 (66.8) | 1301 (98.3) |
| 6 or less | 152 (11.7) | 13 (1.0) |
| 7–12 | 142 (10.9) | 10 (0.8) |
| 13–22 | 106 (8.1) | 0 (0.0) |
| 23–32 | 23 (1.8) | 0 (0.0) |
| 33–42 | 8 (0.6) | 0 (0.0) |
| 43 or more | 2 (0.2) | 0 (0.0) |
| Duration of smoking (years) | ||
| Mean (SD) | 19.7 (7.5) | 12.4 (7.7) |
| Duration of smoking during child’s lifetime (years) | ||
| Mean (SD) | 8.5 (2.1) | 7.5 (3.1) |