Baseline characteristics of the study population stratified by gender and number of chronic pain sites
| Women | Men | |||
| <4 pain sites | 4–9 pain sites | <4 pain sites | 4–9 pain sites | |
| No of persons (%) | 1506 (33.6) | 2978 (66.4) | 1605 (52.8) | 1434 (47.2) |
| Age (years), mean (SD) | 47.9 (13.6) | 50.7 (11.9) | 48.4 (12.1) | 51.8 (11.4) |
| Body mass index (kg/m2), mean (SD) | 26.1 (4.1) | 27.0 (4.5) | 26.5 (3.3) | 27.0 (3.4) |
| Physically inactive, n (%) | 82 (5.4) | 208 (7.0) | 96 (6.0) | 103 (7.2) |
| Education ≤13 years, n (%) | 1142 (75.8) | 2470 (82.9) | 1244 (77.5) | 1220 (85.1) |
| Current smoker, n (%) | 427 (28.4) | 1021 (34.3) | 416 (25.9) | 412 (28.7) |
| Poor/not so good self-rated health, n (%) | 443 (29.4) | 1786 (60.0) | 461 (28.7) | 831 (57.9) |
| Pain-related disability, work and leisure, n (%) | 726 (48.2) | 2034 (68.3) | 784 (48.8) | 970 (67.6) |
| HADS score depression >8, n (%) | 65 (4.3) | 187 (6.3) | 96 (6.0) | 124 (8.6) |
| HADS score anxiety >8, n (%) | 149 (9.9) | 425 (14.3) | 110 (6.9) | 147 (10.3) |
HADS, Hospital Anxiety and Depression Scale.