Table 1.
The odds ratios for suicide related behaviors (intentional self-injury, suicide ideation) at age 22 according to tobacco use behavior in a population-based sample of twins.
| Model 1 (Adjusted for age and sex) |
Model 2 (Adjusted for age, sex, baseline school achievement, depression, impulsivity, alcohol, and parental education) |
|||||
|---|---|---|---|---|---|---|
| Intentional self-injury assessed at age 22 | ||||||
| Age of regular tobacco use initiation (n=1268) | OR | 95%CI | p-value | AOR | 95%CI | p-value |
| Never | 1.00 | 1.00 | ||||
| Late onset tobacco use1 | 3.07 | 1.98,4.75 | 4.6e-07 | 3.24 | 2.02,5.21 | 1.2e-06 |
| Early onset tobacco use2 | 4.32 | 2.00,9.34 | 2.0e-04 | 4.57 | 1.93, 10.8 | .001 |
| Cigarette smoking at baseline (n=1265) | OR | 95%CI | p-value | AOR | 95%CI | p-value |
| Never | 1.00 | 1.00 | ||||
| Experimenting | 1.16 | 0.73,1.86 | .523 | 1.17 | 0.71,1.92 | .526 |
| Occasional | 1.70 | 0.66,4.40 | .271 | 2.12 | 0.74,6.11 | .163 |
| Daily | 3.41 | 1.83,6.34 | 7.2e-05 | 4.45 | 2.04,9.70 | 1.8e-04 |
| Suicide ideation assessed at age 22 | ||||||
| Age of regular tobacco use initiation (n=675 females)3 | OR | 95%CI | p-value | AOR | 95%CI | p-value |
| Never | 1.00 | 1.00 | ||||
| Late onset tobacco use1 | 1.26 | 0.84,1.87 | .264 | 1.34 | 0.86,2.09 | .195 |
| Early onset tobacco use2 | 3.27 | 1.47,7.25 | .004 | 3.69 | 1.56,8.72 | .003 |
| Cigarette smoking at baseline (n=1266) | OR | 95%CI | p-value | AOR | 95%CI | p-value |
| Never | 1.00 | 1.00 | ||||
| Experimenting | 1.27 | 0.92,1.74 | .149 | 1.33 | 0.93,1.89 | .113 |
| Occasional | 1.01 | 0.50,2.05 | .973 | 1.11 | 0.49,2.51 | .796 |
| Daily | 1.33 | 0.73,2.42 | .347 | 1.68 | 0.83,3.41 | .148 |
1
Late-onset tobacco use = ≥ 14 years of age
2
Early–onset tobacco use = <14 years of age
3
Sex interaction: Likelihood-ratio test LR chi2 (2) = 5.21; p= .074