N | 907 | 864 | 1034 | 1019 | 956 | 1141 | 1099 | 1210 | 1233 | 1270 | 1175 |
Male (%) | 62.1 | 60.8 | 59.4 | 59.2 | 58.7 | 62.7 | 64.5 | 66.5 | 66.1 | 64.7 | 65.7 |
Age, years (mean) | 48.8 | 50.0 | 49.8 | 49.9 | 50.3 | 47.7 | 48.1 | 47.7 | 48.9 | 48.7 | 49.4 |
Disease duration, years (mean±SD, median) | 15.7±12.5 | 16.0±12.1 | 15.4±12.0 | 15.8±12.3 | 16.3
±12.2 | 15.3±12.3 | 15.7±12.3 | 16.1±12.1 | 16.8±12.1 | 17.3±12.3 | 18.9±12.3 |
13.0 | 13.0 | 12.0 | 13.0 | 13.3 | 12.0 | 13.0 | 13.1 | 14.3 | 14.9 | 16.9 |
Disease duration at first visit to a rheumatologist, years (mean±SD, median) | 6.8±9.4 | 7.6±9.6 | 7.5±9.8 | 6.9±9.5 | 7.1±9.8 | 5.8±8.9 | 5.5±9.0 | 5.0±7.9 | 5.4±8.2 | 5.6±8.4 | 5.8±8.6 |
| 3.0 | 3.3 | 3.0 | 2.6 | 3.0 | 1.3 | 1.0 | 1.0 | 1.7 | 1.7 | 2.0 |
Disease severity (%) |
Asymptomatic/mild | 24.1 | 20.5 | 20.1 | 16.3 | 16.6 | 31.5 | 26.9 | 33.5 | 34.5 | 28.4 | 29.0 |
(Very) severe | 21.5 | 20.7 | 20.4 | 19.9 | 25.1 | 18.0 | 14.3 | 15.8 | 10.6 | 13.3 | 15.7 |