Demographic and clinical characteristics of the 291 participants
| Age, median (IQR) years | 61 (57–66) |
| Women, n (%) | 257 (88) |
| Fulfilment of ACR hand OA criteria, n (%) | 271 (93) |
| Duration of symptoms, median (IQR) years* | 6 (3–13) |
| Body mass index, mean (SD) kg/m2 | 26.4 (4.8) |
| Assessor-reported tender hand joint count (0–30), median (IQR) joints | 7 (4–11) |
| Self-reported painful hand joint count (0–30), median (IQR) joints | 4 (2–8) |
| Self-reported painful total body joint count (0–18), median (IQR) joints | 4 (2–8) |
| Presence of widespread pain, n (%) | 104 (35.7) |
| PPT painful finger joint, mean (SD) kg/cm2 | 3.9 (1.9) |
| PPT tibialis anterior muscle, mean (SD) kg/cm2 | 5.5 (2.6) |
| Temporal summation, median (IQR) | 1 (0–2) |
| Educational level, n (%) with university or other higher education* | 168 (58) |
| Sleep disturbances, n (%) with moderate to extreme sleep impairment* | 119 (41) |
| Regular use of analgesics, n (%) | 45 (15) |
| HADS total score (0–42), median (IQR)* | 6 (3–10) |
| PCS total score (0–52), median (IQR)* | 9 (5–15) |
| Kellgren-Lawrence sum score (0–128), median (IQR) | 28 (16–43) |
| Sum score of ultrasound-detected osteophytes in bilateral hips, knees and ankles/feet (0–18), median (IQR) | 4 (2–7) |
*Missing values: duration of symptoms n=21, educational level n=1, sleep disturbances n=1, HADS total score n=9, PCS total score n=4.
ACR, American College of Rheumatology; HADS, Hospital Anxiety and Depression Scale; PCS, Pain Catastrophizing Scale; PPT, pressure pain threshold.