Table 2.
Multivariate Cox Proportional Hazards Models of SUD Onset in ADHD Participants
| 2A – Stepwise Selection Model | N | Est. | SE | HR | 95% CI | χ2 | p |
|---|---|---|---|---|---|---|---|
| Overall model | 59 | 15.54 | <0.001 | ||||
| Maternal SUD | 4.01 | 1.04 | 55.04 | (7.1, 425.6) | 14.75 | <0.001 | |
| Paternal warmth (1=high, 4=low) | 1.06 | 0.37 | 2.90 | (1.4, 6.0) | 8.12 | 0.004 |
| 2B – Covariates Added | N | Est. | SE | HR | 95% CI | χ2 | p |
|---|---|---|---|---|---|---|---|
| Overall model | 59 | 17.33 | 0.138 | ||||
| Male gender | 1.34 | 0.89 | 3.80 | (0.7, 21.6) | 2.27 | 0.132 | |
| ODD | 0.29 | 0.82 | 1.34 | (0.3, 6.6) | 0.13 | 0.721 | |
| Maternal SUD | 4.20 | 1.64 | 66.94 | (2.7, 1660.9) | 6.58 | 0.010 | |
| Paternal SUD | −0.82 | 0.82 | 0.44 | (0.1, 2.2) | 1.01 | 0.315 | |
| Maternal ADHD | 0.78 | 0.89 | 2.19 | (0.4, 12.6) | 0.77 | 0.381 | |
| Paternal ADHD | 1.02 | 0.74 | 2.77 | (0.6, 11.8) | 1.89 | 0.170 | |
| Maternal MDD | −0.67 | 0.73 | 0.51 | (0.1, 2.2) | 0.83 | 0.362 | |
| Paternal MDD | −0.44 | 0.92 | 0.65 | (0.1, 3.9) | 0.22 | 0.636 | |
| Maternal anxiety | 0.53 | 0.73 | 1.70 | (0.4, 7.1) | 0.53 | 0.466 | |
| Paternal anxiety | 0.43 | 0.98 | 1.53 | (0.2, 10.5) | 0.19 | 0.662 | |
| Maternal warmth (1=high, 4=low)* | 0.48 | 0.68 | 1.62 | (0.4, 6.2) | 0.50 | 0.479 | |
| Paternal warmth (1=high, 4=low) | 1.50 | 0.52 | 4.49 | (1.6, 12.4) | 8.47 | 0.004 |
*
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, HR=hazard ratio, MDD=major depressive disorder, ODD=oppositional defiant disorder, SE=standard error, SUD=substance use disorder