Model 1 - Hierarchical logistic regression analysis of Moderate to Severe Persistent Post-surgical Pain 4–6 months (T3) following TKA and THA on clinical and psychological measures at baseline (T1).

Note. After removing 2 outliers, this final model correctly predicted 74% of all patients; χ2(6) = 31.696; p<0.001; Nagelkerke R² = 0.412; OR = odds ratioCI = confidence interval; bold = significant at p≤.05; italics = marginally significant p≤.10.

1

Continuous variable, NRS - Numerical Rating Scale (0–10) from BPI-SF: Brief Pain Inventory-Short Form;

2

Continuous variable;

3

Dichotomic variable: 0 = THA: Total Hip Arthroplasty; 1 = TKA: Total Knee Arthroplasty;

a

Continuous variable, HADS-A: Hospital Anxiety and Depression Scale - anxiety subscale;

b

Continuous variables, subscales of IPQ-R: Illness Perception Questionnaire Revised.