Table 3.
Descriptives of outcome and confounders by frequency of cigarette use at age 16% (n)
| Freq of cigarette use age 16 | Never 56.0 (973) | Experimenter 34.2 (615) | Weekly 4.1 (77) | Daily 5.7 (91) | p value |
|---|---|---|---|---|---|
| Family history of depression | 25.2 (245) | 28.1 (173) | 23.4 (18) | 31.9 (29) | 0.175 |
| Family history of schizophrenia | 0.9 (9) | 0.8 (5) | 0 | 1.1 (1) | 0.770 |
| No higher maternal education | 73.9 (719) | 74.0 (455) | 77.9 (60) | 80.2 (73) | 0.208 |
| Urban dwelling | 88.5 (861) | 88.6 (545) | 89.6 (69) | 86.8 (79) | 0.842 |
| Gender (female) | 51.1 (497) | 67.5 (415) | 71.4 (55) | 63.7 (58) | <0.001 |
| Borderline personalitya | 1.3 (13) | 1.3 (8) | 0 | 1.1 (1) | 0.582 |
| IQ at age 8 m(sd) | 110.0 (15.4) | 110.9 (15.3) | 110.2 (13.7) | 108.0 (15.9) | 0.714 |
| Depression at age 12b | 2.0 (19) | 2.8 (17) | 3.9 (3) | 3.3 (3) | 0.169 |
| Early onset persistent conduct disorder groupc | 5.3 (52) | 6.7 (41) | 7.8 (6) | 11.0 (10) | 0.024 |
| Peer problems (4 or more) | 7.4 (72) | 6.7 (41) | 1.3 (1) | 12.1 (11) | 0.859 |
| Bullied | 29.9 (291) | 30.9 (190) | 26.0 (20) | 29.7 (27) | 0.880 |
| Ever used cannabis age 16 | 4.9 (48) | 47.5 (292) | 77.9 (60) | 89.0 (81) | <0.001 |
| Used other illicit drugs age 16 | 5.1 (50) | 20.8 (128) | 45.5 (35) | 65.9 (60) | <0.001 |
| Hazardous alcohol use age 16 | 15.1 (147) | 51.2 (315) | 70.1 (54) | 72.5 (66) | <0.001 |
a
Those with a score of 4 or over.
b
Those with a score of 17 or over.
c
As reported in Barker & Maughan (2009).