Table 1.
General characteristics of the study population
| Cohort | RSI | RSII | RSIII |
| Hand | |||
| n (OA cases) | 4829 (1830) | 1791 (688) | 2071 (526) |
| Female (%) | 2773 (0.57) | 964 (0.54) | 1180 (0.57) |
| Age (SD) | 67.6 (7.9) | 64.6 (7.9) | 57.1 (7.0) |
| KLsum (aver. (SD)) | 8.4 (9.9) | 6.9 (4.0) | 4.7 (6.5) |
| Osteophytes (aver. (SD)) | 7.1 (7.8) | 6.8 (8.2) | 4.6 (6.3) |
| JSN (aver. (SD)) | 0.84 (2.4) | 0.34 (1.3) | 0.2 (0.8) |
| Finger | |||
| n (OA cases) | 4839 (1244) | 1803 (474) | 2072 (298) |
| Female (%) | 2779 (0.57) | 972 (0.54) | 1181 (0.57) |
| Age (SD) | 67.6 (7.9) | 64.6 (7.9) | 57.1 (7.0) |
| KLsum (aver. (SD)) | 5.8 (7.4) | 4.5 (6.1) | 3.0 (4.7) |
| Osteophytes (aver. (SD)) | 4.7 (5.5) | 4.3 (5.8) | 2.9 (4.5) |
| JSN (aver. (SD)) | 0.6 (1.9) | 0.25 (1.1) | 0.1 (0.7) |
| Thumb | |||
| n (OA cases) | 4882 (916) | 1813 (255) | 2083 (166) |
| Female (%) | 2785 (0.57) | 972 (0.54) | 1184 (0.57) |
| Age (SD) | 67.6 (7.9) | 64.6 (7.9) | 57.1 (7.0) |
| KLsum (aver. (SD)) | 2.1 (3.3) | 1.2 (2.3) | 0.8 (1.7) |
| Osteophytes (aver. (SD)) | 1.3 (2.1) | 0.93 (1.7) | 0.6 (1.3) |
| JSN (aver. (SD)) | 0.4 (1.0) | 0.18 (0.63) | 0.1 (0.4) |
aver., average; JSN, joint space narrowing; KL, Kellgren-Lawerence; OA, osteoarthritis; RS, Rotterdam Study.