Results of univariable logistic regression analyses of baseline characteristics associated with subgroup membership (Subgroup 1 ‘good outcome’ (n=330) used as the reference group)
| Characteristic | Subgroup 2 ‘moderate outcome’ (n=257) | Subgroup 3 ‘poor outcome’ (n=110) | ||
|---|---|---|---|---|
| OR (95% CI) | p Value | OR (95% CI) | p Value | |
| Age, years | 0.99 (0.95 to 1.02) | 0.35 | 0.98 (0.94 to 1.02) | 0.34 |
| Female | 1.26 (0.83 to 1.91) | 0.29 | 1.33 (0.75 to 2.35) | 0.33 |
| Body mass index, kg/m2 | 1.13 (1.08 to 1.18) | <0.0001 | 1.16 (1.10 to 1.23) | <0.0001 |
| NRS for knee pain (0–10) | 1.40 (1.27 to 1.53) | <0.0001 | 1.90 (1.65 to 2.18) | <0.0001 |
| Bilateral knee pain | 0.96 (0.70 to 1.34) | 0.83 | 1.63 (1.04 to 2.56) | 0.03 |
| Morning stiffness knee | 1.37 (0.96 to 1.96) | 0.08 | 2.62 (1.51 to 4.57) | 0.0006 |
| Bony tenderness | 1.65 (1.18 to 2.29) | 0.003 | 2.58 (1.64 to 4.05) | <0.0001 |
| Crepitus | 0.81 (0.59 to 1.13) | 0.22 | 1.20 (0.77 to 1.86) | 0.41 |
| Active knee flexion range, degrees | 0.97 (0.95 to 0.99) | 0.0008 | 0.95 (0.93 to 0.97) | <0.0001 |
| Hip pain | 1.89 (1.36 to 2.62) | 0.0002 | 2.70 (1.72 to 4.22) | <0.0001 |
| Osteophytosis | 1.26 (0.82 to 1.96) | 0.30 | 1.77 (1.04 to 3.01) | 0.03 |
| Joint space narrowing | 1.61 (1.00 to 2.59) | 0.05 | 2.13 (1.21 to 3.74) | 0.009 |
| Comorbidity count ≥3 | 2.50 (1.64 to 3.80) | <0.0001 | 5.46 (3.32 to 8.97) | <0.0001 |
| SF-36 vitality (0–100) | 0.97 (0.96 to 0.98) | <0.0001 | 0.94 (0.92 to 0.95) | <0.0001 |
| PCI resting (5–20) | 1.13 (1.05 to 1.21) | 0.0009 | 1.39 (1.26 to 1.52) | <0.0001 |
NRS, numeric rating scale; PCI, Pain Coping Inventory; SF-36, Short-Form 36 Health Survey.