Table 2.
Mediation and Moderation Analyses
| Model | Independent Variable | Dependent Variable | Model | p | b | SE | t | 95% CI | |
|---|---|---|---|---|---|---|---|---|---|
| Lower | Upper | ||||||||
| Anxiety Model | |||||||||
| 1 | ETI-SR Total Score | Promis Anxiety T-score | R2=0.14, F(4, 305)=13.0, p<.001 | <.001 | 0.54 | 0.08 | 6.92 | 0.34 | 0.69 |
| 2 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.20, F(4, 305)=18.9, p<.001 | <.001 | 0.23 | 0.03 | 7.84 | 0.17 | 0.29 |
| 3 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.22, F(5, 305)=17.01 p<.001 | <.001 | 0.20 | 0.03 | 6.43 | 0.14 | 0.26 |
| Promis Anxiety T-score | OUD Symptoms (#) | 0.01 | 0.06 | 0.02 | 2.63 | 0.01 | 0.10 | ||
| Indirect Effect (mediator = Promis Anxiety T-score)b | 0.03 | 0.01 | 0.01 | 0.06 | |||||
| Depression Model | |||||||||
| 1 | ETI-SR Total Score | Promis Depression T-score | R2=0.14, F(4, 305)=12.3, p<.001 | <.001 | 0.51 | 0.07 | 6.96 | 0.37 | 0.66 |
| 2 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.20, F(4, 305)=18.79, p<.001 | <.001 | 0.23 | 0.03 | 7.84 | 0.17 | 0.29 |
| 3 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.23, F(5, 305)=18.26, p<.001 | <.001 | 0.19 | 0.03 | 6.14 | 0.13 | 0.25 |
| Promis Depression T-score | OUD Symptoms (#) | <.001 | 0.08 | 0.02 | 3.62 | 0.04 | 0.12 | ||
| Indirect Effect (mediator = Promis Depression T-score)b | 0.04 | 0.01 | 0.02 | 0.07 | |||||
| Perceived Stress Model | |||||||||
| 1 | ETI-SR Total Score | Perceived Stress Scale | R2=0.09, F(4, 305)=7.63, p<.001 | <.001 | 0.25 | 0.05 | 4.84 | 0.15 | 0.35 |
| 2 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.20, F(4, 305)=18.8, p<.001 | <.001 | 0.23 | 0.03 | 7.84 | 0.17 | 0.29 |
| 3 | ETI-SR Total Score | OUD Symptoms (#)a | R2=0.25, F(5, 305)=20.6, p<.001 | <.001 | 0.19 | 0.03 | 6.63 | 0.14 | 0.25 |
| Perceived Stress Scale | OUD Symptoms (#) | <.001 | 0.15 | 0.03 | 4.73 | 0.09 | 0.21 | ||
| Indirect Effect (mediator = Perceived Stress Scale)b | 0.04 | 0.01 | 0.02 | 0.06 | |||||
| Multiple Mediation Model | |||||||||
| 1 | ETI-SR Total Score | Promis Depression T-score | R2=0.14, F(4, 305)=12.9, p<.001 | <.001 | 0.51 | 0.74 | 6.96 | 0.37 | 0.66 |
| 2 | ETI-SR Total Score | Promis Anxiety T-score | R2=0.15, F(4, 305)=13.0, p<.001 | <.001 | 0.54 | 0.08 | 6.91 | 0.38 | 0.69 |
| 3 | ETI-SR Total Score | Perceived Stress Scale | R2=0.09, F(4, 305)=7.63, p<.001 | <.001 | 0.25 | 0.05 | 4.84 | 0.15 | 0.35 |
| 4 | ETI-SR Total Score | OUD Symptoms (#)c | R2=0.20, F(4, 305)=18.9, p<.001 | <.001 | 0.23 | 0.03 | 7.84 | 0.17 | 0.29 |
| 5 | ETI-SR Total Score | OUD Symptoms (#)c | R2=0.25, F(7, 302)=14.76, p<.001 | <.001 | 0.19 | 0.03 | 6.17 | 0.13 | 0.25 |
| Promis Depression T-score | OUD Symptoms (#) | 0.37 | 0.03 | 0.04 | 0.90 | −0.04 | 0.11 | ||
| Promis Anxiety T-score | OUD Symptoms (#) | 0.66 | −0.01 | 0.03 | −0.44 | −0.08 | 0.05 | ||
| Perceived Stress Scale | OUD Symptoms (#) | <.001 | 0.13 | 0.04 | 3.11 | 0.05 | 0.21 | ||
| Indirect Effect (mediator = Promis Anxiety T-score)b | −0.01 | 0.02 | −0.05 | 0.03 | |||||
| Indirect Effect (mediator = Promis Depression T-score)b | 0.02 | 0.02 | −0.02 | 0.06 | |||||
| Indirect Effect (mediator = Perceived Stress Scale)b | 0.03 | 0.02 | 0.01 | 0.06 | |||||
| Anxiety Moderation Model | R2=0.23, F(6, 303)=15.10, p<.001 | ||||||||
| OUD Symptoms (#) | ETI-SR Total Score | <.001 | 0.19 | 0.03 | 6.18 | 0.13 | 0.25 | ||
| Promis Anxiety T-score | 0.01 | 0.06 | 0.02 | 2.74 | 0.02 | 0.10 | |||
| Interaction | 0.04 | 0.01 | 0.00 | 2.07 | 0.00 | 0.01 | |||
| 16% | <.001 | 0.14 | 0.04 | 3.12 | 0.05 | 0.22 | |||
| 50% | <.001 | 0.20 | 0.03 | 6.35 | 0.14 | 0.26 | |||
| 84% | <.001 | 0.25 | 0.04 | 6.44 | 0.17 | 0.32 | |||
| Depression Moderation Model | R2=0.25, F(6, 303)=16.5, p<.001 | ||||||||
| OUD Symptoms (#) | ETI-SR Total Score | <.001 | 0.18 | 0.03 | 6.02 | 0.12 | 0.24 | ||
| Promis Depression T-score | <.001 | 0.08 | 0.02 | 3.74 | 0.04 | 0.13 | |||
| Interaction | 0.03 | 0.01 | 0.00 | 2.24 | 0.00 | 0.01 | |||
| 16% | <.001 | 0.13 | 0.04 | 3.16 | 0.05 | 0.21 | |||
| 50% | <.001 | 0.19 | 0.03 | 6.11 | 0.13 | 0.25 | |||
| 84% | <.001 | 0.24 | 0.04 | 6.32 | 0.16 | 0.31 | |||
| Perceived Stress Moderation Model | R2=0.26, F(6, 303)=17.4, p<..001 | ||||||||
| OUD Symptoms (#) | ETI-SR Total Score | <.001 | 0.19 | 0.03 | 6.57 | 0.14 | 0.25 | ||
| Perceived Stress Scale Score | <.001 | 0.15 | 0.03 | 4.65 | 0.09 | 0.21 | |||
| Interaction | 0.79 | 0.00 | 0.00 | 0.26 | −0.01 | 0.01 | |||
Only significant models are presented.
OUD=opioid use disorder; ETI-SR= Early Trauma Inventory Self-Report, SE= standard error, CI=confidence interval
a.
Model 2=total effect and Model 3=direct effect of early life trauma on opioid use disorder severity in the univariate mediation analyses.
b.
T-scores and p-values not available for this method; indirect effects that do not include 0 in the confidence interval are significant.
c.
Model 4=total effect and Model 5=direct effect in the multiple mediation analysis.