Table 1.
Baseline descriptive characteristics of the study participants
| Baseline Characteristic | All eligible baseline participants (n = 558) | Participants without repeat digital hand photos at 7 years (n = 305) | Participants with repeat digital hand photos at 7 years (n = 253) |
|---|---|---|---|
| % Female (no.) | 61.6 (344) | 62.6 (191) | 60.5 (153) |
| Age range, years | 51–91 | 51–91 | 51 to 80 |
| Mean age, years (s.d.) | 64.2 (8.2) | 65.4 (8.8) | 62.7 (7.0) |
| Mean BMI (s.d.) | 28.2 (4.8) | 28.7 (4.9) | 27.7 (4.6) |
| % Attended further education (no.) | 16.2 (89) | 13.1 (39) | 19.8 (50) |
| % Manual occupational class (no.) | 52.3 (274) | 57.2 (162) | 46.7 (112) |
| % Right-handed (no.) | 90.8 (504) | 89.8 (274) | 90.9 (230) |
| % Hand pain or problems in the last month (no.) | 85.8 (479) | 87.5 (267) | 83.8 (212) |
| % Thumb pain during activity in the last month % (no.) | 53.0 (296) | 56.4 (172) | 49.0 (124) |
| Duration of hand symptoms % (no.): | |||
| < 1 year | 10.3 (53) | 10.3 (29) | 10.2 (24) |
| 1–5 years | 42.3 (218) | 41.8 (118) | 42.4 (100) |
| > 5–10 years | 22.5 (116) | 21.3 (60) | 23.7 (56) |
| > 10 years | 24.9 (128) | 25.5 (72) | 23.7 (56) |
| Summed photographic hand OA score for the 3 joint groups % (no.): | |||
| 0 | 42.6 (229) | 38.2 (112) | 48.0 (117) |
| 1 | 18.8 (101) | 19.8 (58) | 17.6 (43) |
| 2 | 15.1 (81) | 14.0 (41) | 16.4 (40) |
| 3 | 8.9 (48) | 9.9 (29) | 7.8 (19) |
| ≥ 4 | 14.5 (78) | 18.1 (53) | 10.2 (25) |
| Clinical hand OA % (no.): | |||
| ACR criteria | 29.6 (165) | 29.8 (91) | 29.4 (74) |
| Relaxed ACR criteria* | 51.0 (284) | 51.8 (158) | 50.0 (126) |
| Radiographic OA % (no.): | |||
| KL ≥ 2 in ≥1 joint | 76.5 (427) | 78.4 (239) | 74.3 (188) |
| KL ≥ 3 in ≥1 joint | 35.8 (200) | 40.3 (123) | 30.4 (77) |
* Relaxed ACR criteria is when there is pain on some, most or all days rather than most days or all days in the ACR criteria. s.d., standard deviation; BMI, Body mass Index; ACR, American College of Rheumatology; KL, Kellgren and Lawrence grading system