Table II.
Descriptive characteristics of the symptomatic hand OA subsets (n = 1076)
| Overall | Unclassified∗ | Erosive OA | Generalised hand OA | IPJ and thumb base OA | Thumb base OA | Nodal IPJ OA | Non-nodal IPJ OA | |
|---|---|---|---|---|---|---|---|---|
| Frequency in study population % (no.) | 100% (1076) | 35.3% (380) | 4.8% (52) | 15.2% (164) | 9.0% (97) | 22.5% (242) | 7.6% (82) | 5.5% (59) |
| Age, mean (s.d.) | 64.8 (8.3) | 60.9 (7.4) | 70.1 (8.1) | 69.6 (8.0) | 67.2 (7.0) | 65.1 (8.2) | 65.3 (7.1) | 65.5 (8.1) |
| % Female (no.) | 60.4% (650) | 52.9% (201) | 82.7% (43) | 73.2% (120) | 67.0% (65) | 55.0% (133) | 63.4% (52) | 61.0% (36) |
| BMI, mean (s.d.) | 29.1 (5.1) | 29.2 (4.9) | 28.7 (4.9) | 29.2 (5.2) | 29.5 (5.3) | 28.8 (5.0) | 30.0 (6.1) | 28.6 (4.4) |
| % Manual occupational class (no.) | 53.5% (540) | 58.0% (206) | 54.3% (25) | 51.6% (81) | 48.9% (44) | 48.2% (109) | 51.2% (41) | 61.8% (34) |
| % Attended higher education (no.) | 15.9% (167) | 14.0% (52) | 17.6% (9) | 14.6% (23) | 23.4% (22) | 16.0% (38) | 14.6% (12) | 18.6% (11) |
| % Pain on most or all days in the last month (no.) | 43.6% (469) | 35.8% (136) | 55.8% (29) | 45.7% (75) | 44.3% (43) | 49.6% (120) | 50.0% (41) | 42.4% (25) |
| % Radiographic hand OA (K&L ≥ 2 in ≥2 joints) (no.) | 61.9% (666) | 7.4% (28) | 100.0% (52) | 100.0% (164) | 100.0% (97) | 76.0% (184) | 100.0% (82) | 100.0% (59) |
| Number of joints K&L ≥ 2 (0–20), mean (s.d.) | 3.7 (4.1) | 0.4 (0.7) | 12.2 (4.1) | 9.0 (3.7) | 5.5 (1.6) | 2.3 (1.1) | 5.0 (3.1) | 4.3 (2.2) |
| Number of joints K&L ≥ 3 (0–20), mean (s.d.) | 1.4 (2.6) | <0.1 (0.2) | 8.8 (4.1) | 2.8 (3.0) | 2.0 (2.0) | 0.8 (0.9) | 1.1 (1.6) | 0.8 (1.4) |
| Number of joints K&L = 4 (0–20), mean (s.d.) | 0.6 (1.6) | <0.1 (0.1) | 5.3 (3.4) | 1.1 (1.7) | 0.7 (1.3) | 0.3 (0.6) | 0.4 (0.8) | 0.1 (0.4) |
| Total K&L score (0–80), mean (s.d.) | 10.8 (11.8) | 1.8 (2.2) | 39.8 (14.0) | 23.8 (10.3) | 15.4 (5.8) | 7.0 (3.4) | 13.4 (7.2) | 11.4 (6.3) |
| % Symptomatic radiographic knee OA (no.)† | 58.3% (595) | 56.4% (207) | 54.2% (26) | 65.6% (103) | 66.7% (60) | 54.6% (125) | 60.0% (45) | 52.7% (29) |
| % Symptomatic moderate–severe radiographic knee OA (no.)‡ | 29.3% (302) | 20.2% (74) | 37.5% (18) | 41.4% (65) | 40.0% (36) | 31.4% (72) | 30.7% (23) | 25.5% (14) |
Analysis was completed on CASHA and CASK study participants using mutually exclusive subsets as determined in Fig. 1.
Individuals in this sub-group are symptomatic with pain in the last month and may have some radiographic changes, but they do not meet the criteria for any of the hand OA subsets.
Symptomatic radiographic knee OA is knee pain in the last month and radiographic OA of tibiofemoral or patella–femoral joints of either knee (K&L ≥ 2 on PA and/or skyline views and/or posterior or lateral osteophytes ≥1 on lateral view).
Symptomatic moderate–severe radiographic knee OA is knee pain in the last month and moderate to severe radiographic OA of tibiofemoral or patella–femoral joints of either knee (K&L ≥ 3 on PA and/or skyline views and/or posterior or lateral osteophytes ≥3 on lateral view); s.d., standard deviation; data was missing for the following characteristics: BMI n = 2 (0.3%), manual occupational class n = 67 (6.2%), attended higher education n = 23 (2.1%), symptomatic radiographic knee OA n = 55 (5.1%) and symptomatic moderate–severe radiographic knee OA n = 55 (5.1%).