Sample characteristics and results for non-parametric group comparison tests (Mann-Whitney and Chi-Square) between pain groups (T3), on socio-demographic, clinical and psychological measures at T1 and T2.

Note. Continuous variables are presented as median (range); categorical variables are presented as n (%); T1–24 hours before surgery; T2–48 hours after surgery; T3–4–6 months after surgery;1BMI = body mass index;2Comorbidities total = number of comorbid health conditions;3NRS(BPI) = Numerical Rating Scale 0–10 from Brief Pain Inventory;4Pain Total Interference Scale 0–70 from Brief Pain Inventory (BPI);5Type of anesthesia: Anesthesia loco-regional alone: BSA or epidural vs Anesthesia loco-regional (BSA or epidural)+peripheral nerve blocks (PNB);6Pain Frequency: constant pain vs intermittent or brief pain, assessed via frequency subscale of McGill Pain Questionnaire;aHADS = Hospital Anxiety and Depression Scale;bIPQ-R = Illness Perception Questionnaire-Revised.