Table 1.
Baseline characteristics for the analytic sample by phenotype group.
| Characteristic* | Phenotypes | ||||
|---|---|---|---|---|---|
| No Phenotype N = 2426 (76.9%) |
Bone N = 531 (16.8%) |
Meniscus/Cartilage N = 75 (2.4%) |
Inflammatory N = 38 (1.2%) |
Hypertrophy N = 84 (2.6%) |
|
| Age, years | 60 (53–69) | 59 (53–68) | 67 (60–72) | 63 (57–70.8) | 64 (54.8–70) |
| P value | – | 0.25 | < 0.001 | 0.10 | 0.10 |
| Sex Female, No. (%) | 1383 (57.0) | 326 (61.4) | 29 (38.7) | 18 (47.4) | 26 (66.7) |
| P value | – | 0.13 | < 0.001 | 0.31 | 0.13 |
| BMI kg /m2 | 27.7 (24.6–31.1) | 28.8 (26.0–32.2) | 28.7 (26.1–32) | 27.6 (25.8–29.5) | 32.8 (29.9–35.4) |
| P value | – | < 0.001 | 0.07 | 0.84 | < 0.001 |
| Baseline KL grade, No. (%) | |||||
| 0 and 1 | 1544 (63.6) | 201 (37.9) | 5 (6.7) | 8 (21.1) | 4 (4.8) |
| 2 | 624 (25.7) | 204 (38.4) | 21(28.0) | 14(36.8) | 41 (48.8) |
| 3 | 242 (10.0) | 100 (18.8) | 38(50.7) | 15(39.5) | 35 (41.7) |
| 4 | 16 (0.7) | 26 (4.9) | 11(14.7) | 1(2.6) | 4 (4.8) |
| P value | – | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
| Baseline KOOS pain score | 97.2 (78.2–100) | 83.3 (66.7–6.9) | 77.8 (68.1–95.8) | 69.1 (50.7–85.7) | 75.0 (59.7–88.9) |
| P value | – | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
| Baseline radiographic OA, No. (%) | 882 (36.4) | 330 (62.1) | 70 (93.3) | 30 (78.9) | 80 (95.2) |
| P value | – | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
| Baseline symptomatic OA, No. (%) | 1047 (43.2) | 373 (70.2) | 52 (69.3) | 30 (78.9) | 60 (71.4) |
| P value | – | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
*Median (interquartile range) or percentage.
-: not applicable, BMI: body mass index, KL: Kellgren-Lawrence, KOOS: Knee Injury and Osteoarthritis Outcome Score.