Table 3.
Model comparison.
| Model | Type | AIC | Predictors | OR (CI) | β (CI) |
|---|---|---|---|---|---|
| Model 0 | PO | 426.7 | Intercept only | n/a | n/a |
| Model 1 | PO | 415.7 | * Fibromyalgia | 3.32 (1.72–6.55) | 1.20 (0.54–1.88) |
| Model 2 | PO | 418.2 | * Fibromyalgia | 2.78 (1.39–5.57) | 1.02 (0.33–1.73) |
| Age | 1.03 (0.99–1.07) | 0.03 (−0.01–0.07) | |||
| Sex | 1.10 (0.59–2.05) | 0.09 (−0.52–0.72) | |||
| Mental Health | 0.99 (0.98–1.01) | −0.01 (−0.02–0.01) | |||
| OUD Severity (DSM-5) | 1.12 (0.94–1.34) | 0.12 (−0.06–0.29) | |||
| Model 3 | PO | 410.7 | * Fibromyalgia | 2.29 (1.13–4.71) | 0.83 (0.12–1.55) |
| Very Mild Pain | 1.83 (0.36–9.38) | 0.60 (−1.02–2.23) | |||
| Mild Pain | 1.39 (0.38–5.01) | 0.33 (−1.00–1.61) | |||
| Moderate Pain | 2.96 (0.92–9.55) | 1.06 (−0.08–2.26) | |||
| *Severe Pain | 6.14 (1.65–23.4) | 1.82 (0.50–3.15) | |||
| *Very Severe Pain | 6.79 (1.75–26.7) | 1.92 (0.56–3.29) | |||
| Model 4 | PPO | 402.5 | * Fibromyalgia | 2.25 (1.10–4.61) | 0.81 (0.10–1.53) |
| Very Mild Pain | 2.10 (0.40–11.2) | 0.74 (−0.93–2.41) | |||
| Mild Pain | 1.61 (0.45–5.78) | 0.48 (−0.80–1.75) | |||
| * Moderate Pain | 3.71 (1.14–12.1) | 1.31 (0.13–2.49) | |||
| * Severe Pain | 8.32 (2.20–31.6) | 2.11 (0.79–3.45) | |||
| Very Severe Pain (P[Y ≥ 2]) | 0.89 (0.19–4.04) | −0.12 (−1.64–1.40) | |||
| Very Severe Pain (P[Y ≥ 3]) | 3.41 (0.83–14.1) | 1.22 (−0.19–2.65) | |||
| * Very Severe Pain (P[Y ≥ 4]) | 6.77 (1.66–27.5) | 1.91 (0.51–3.31) | |||
| * Very Severe Pain (P[Y ≥ 5]) | 13.0 (3.21–52.2) | 2.56 (1.17–3.96) | |||
| Model 5 (Pain severity only) |
PPO | 405.6 | Very Mild Pain | 2.01 (0.38–10.7) | 0.70 (−0.97–2.37) |
| Mild Pain | 2.07 (0.58–7.35) | 0.73 (−0.54–2.00) | |||
| *Moderate Pain | 4.28 (1.32–13.9) | 1.5 (0.27–2.63) | |||
| *Severe Pain | 11.5 (3.06–42.8) | 2.44 (1.12–3.76) | |||
| Very Severe Pain (P[Y ≥ 2]) | 1.36 (0.31–5.89) | 0.31 (−1.16–1.77) | |||
| *Very Severe Pain (P[Y ≥ 3]) | 5.23 (1.33–20.6) | 1.65 (0.28–3.02) | |||
| *Very Severe Pain (P[Y ≥ 4]) | 10.2 (2.62–39.8) | 2.32 (0.96–3.68) | |||
| *Very Severe Pain (P[Y ≥ 5]) | 19.5 (5.03–75.5) | 2.97 (1.62–4.32) |
Notes: AIC = Akaike Information Criterion, lower AIC indicates better model fit; OR = Odds Ratio reflecting the odds of agreement with the statement ‘I have tried to stop using opioids before, but pain caused me to relapse’; CI = 95% Confidence Interval; PO = Proportional Odds Ordinal Logistic Regression; PPO = Partial Proportional Odds Ordinal Logistic Regression; P[Y ≥] = Because the predictor Very Severe Pain is allowed to vary across dependent variable response categories in the PPO model, and because the dependent variable has 5 possible responses, 4 sub-models are fitted as represented in the table. Pain Severity categories are dummy coded responses to the Research and Development Corporation 36-Item Health Survey (RAND-36) item 21 which asks respondents ‘How much bodily pain have you had during the past 4 weeks?’ * = Statistically significant predictor in model (p < 0.05).