Table 5.
Cox regression model predicting persistence of smoking during follow-up in adolescents who had prior smoking history at intake
| β (SE) | Wald | OR (CI) | p | |
|---|---|---|---|---|
| Model 1 | ||||
| Smoking at intake (current smoker) | −0.32 (0.48) | 0.44 | 0.73 (0.29-1.86) | NS |
| Stress at intake | 0.09 (0.06) | 2.24 | 1.09 (0.97-1.22) | NS |
| Model 2 | ||||
| Smoking at intake (current smoker) | 0.40 (0.57) | 0.50 | 1.49 (0.49-4.53) | NS |
| Stress at baseline | 0.09 (0.08) | 1.27 | 1.09 (0.94-1.27) | NS |
| HPA activity1 | 0.85 (0.33) | 6.59 | 2.34 (1.22-4.48) | .01 |
| Stress at follow-up | 0.20 (0.18) | 1.25 | 1.23 (0.86-1.75) | NS |
| HPA activity × stress at follow-up | 0.10 (0.18) | 0.33 | 1.11 (0.78-1.56) | NS |
SE = standard error; OR = odds-ratio; CI = confidence interval; HPA (hypothalamic-pituitary-adrenal)
1
HPA activity (a composite measure of evening/night-time cortisol levels)
Model 1: χ2 = 2.45, df = 2, NS; δχ2 = 2.42, df = 2, NS
Model 2: χ2 = 15.53, df = 5, p = .008; δχ2 = 10.80, df = 3, p = .01