| Country | No. of sites | No. of patients | Female % | Non-Caucasians % | Age, mean | Education years mean | BMI, female mean | BMI, male mean | Disease duration years mean | RF+ % | Extra-articular disease* % |
| Denmark | 3 | 301 | 76.7 | 1.7 | 57.8 | 10.73 | 24.6 | 25.5 | 12.0 | 73.7 | 33.9 |
| Finland | 3 | 304 | 72.4 | 0.3 | 58.5 | 10.36 | 26.7 | 26.5 | 13.5 | 75.1 | 17.8 |
| France | 4 | 389 | 77.9 | 6.7 | 55.3 | 10.86 | 24.8 | 25.2 | 12.8 | 75.3 | 20.6 |
| Germany | 3 | 225 | 83.6 | 1.3 | 58.8 | 10.40 | 26.1 | 27.6 | 13.4 | 61.4 | 35.6 |
| Ireland | 3 | 225 | 64.3 | 3.1 | 56.7 | 11.59 | 25.3 | 25.5 | 11.5 | 81.0 | 29.9 |
| Italy | 4 | 336 | 78.2 | 0.9 | 61.0 | 8.34 | 25.2 | 26.0 | 10.5 | 72.7 | 13.0 |
| The Netherlands | 3 | 317 | 66.2 | 4.1 | 59.2 | 11.26 | 26.0 | 25.2 | 9.2 | 68.8 | 12.9 |
| Poland | 7 | 642 | 86.7 | 0.6 | 53.2 | 12.02 | 25.4 | 25.3 | 11.5 | 70.8 | 33.5 |
| Spain | 3 | 301 | 74.3 | 2.0 | 59.9 | 10.38 | 26.3 | 26.8 | 10.8 | 71.4 | 22.9 |
| Sweden | 3 | 248 | 72.1 | 1.2 | 59.5 | 10.42 | 25.2 | 25.3 | 12.4 | 82.0 | 22.6 |
| UK | 3 | 126 | 77.8 | 16.7 | 60.2 | 12.71 | 24.7 | 25.8 | 15.5 | 84.4 | 30.4 |
| Turkey | 3 | 309 | 85.6 | 2.9 | 51.9 | 7.37 | 27.3 | 26.4 | 11.6 | 68.7 | 18.1 |
| Serbia | 1 | 100 | 88.0 | 0 | 59.2 | 8.55 | 25.9 | 24.6 | 10.1 | 71.4 | 23.0 |
| USA | 3 | 294 | 72.3 | 32.4 | 57.4 | 13.49 | 28.2 | 27.9 | 9.3 | 69.9 | 24.1 |
| Argentina | 2 | 246 | 90.2 | 93.9 | 51.4 | 9.42 | 26.3 | 25.2 | 9.9 | 90.5 | 26.5 |
| Total | 48 | 4363 | 78.0 | 9.8 | 56.8 | 10.66 | 25.9 | 26.0 | 11.5 | 73.7 | 24.4 |
BMI, body mass index; QUEST-RA, Quantitative Patient Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis; RF, rheumatoid factor.
*Includes nodules, pulmonal fibrosis, pericarditis, Felty’s and scleritis.
A file including standard deviations of variables is provided in the supplementary material.