Table 3.
Multivariate Cox Proportional Hazards Models of SUD Onset in ADHD and HC Participants
| 3A – Stepwise Selection Model | N | Est. | SE | HR | 95% CI | χ2 | p |
|---|---|---|---|---|---|---|---|
| Overall model | 122 | 18.82 | <0.001 | ||||
| ADHD | 1.92 | 0.79 | 6.85 | (1.5, 32.1) | 5.97 | 0.015 | |
| Maternal SUD | 3.03 | 0.85 | 20.64 | (3.9, 108.7) | 12.76 | <0.001 | |
| Paternal warmth (1=high, 4=low) | 0.97 | 0.32 | 2.64 | (1.4, 4.9) | 9.21 | 0.002 |
| 3B – Covariates Added | N | Est. | SE | HR | 95% CI | χ2 | p |
|---|---|---|---|---|---|---|---|
| Overall model | 122 | 27.70 | 0.010 | ||||
| Male gender | 1.89 | 0.85 | 6.65 | (1.3, 35.2) | 4.96 | 0.026 | |
| ADHD | 1.50 | 0.92 | 4.49 | (0.7, 27.0) | 2.69 | 0.101 | |
| ODD | −0.32 | 0.76 | 0.73 | (0.2, 3.2) | 0.18 | 0.673 | |
| Maternal SUD | 3.11 | 0.99 | 22.44 | (3.3, 154.7) | 9.97 | 0.002 | |
| Paternal SUD | −0.58 | 0.71 | 0.56 | (0.1, 2.3) | 0.67 | 0.414 | |
| Maternal ADHD | 1.27 | 0.75 | 3.55 | (0.8, 15.6) | 2.82 | 0.093 | |
| Paternal ADHD | 0.77 | 0.68 | 2.15 | (0.6, 8.2) | 1.26 | 0.261 | |
| Maternal MDD | −1.09 | 0.65 | 0.34 | (0.1, 1.2) | 2.84 | 0.092 | |
| Paternal MDD | −0.80 | 0.72 | 0.45 | (0.1, 1.9) | 1.22 | 0.269 | |
| Maternal anxiety | 1.69 | 0.69 | 5.43 | (1.4, 20.9) | 6.05 | 0.014 | |
| Paternal anxiety | 0.71 | 0.72 | 2.04 | (0.5, 8.4) | 0.98 | 0.322 | |
| Maternal warmth (1=high, 4=low)* | 0.99 | 0.67 | 2.69 | (0.7, 9.9) | 2.20 | 0.138 | |
| Paternal warmth (1=high, 4=low) | 1.25 | 0.41 | 3.50 | (1.6, 7.8) | 9.30 | 0.002 |
*
Maternal warmth was measured on a 1–4 scale, although no participants had scores of 3 or 4;
ADHD=attention-deficit/hyperactivity disorder, CI=confidence interval, Est.=Estimate, HC=healthy control, HR=hazard ratio, MDD=major depressive disorder, ODD=oppositional defiant disorder, SE=standard error, SUD=substance use disorder