Table 2. Associations of baseline predictors (independent variables) with membership in each of the four dual trajectory groups.
Adjusted relative risk ratios (95% confidence intervals) from multivariable multinomial logistic regression models (Reference group: Group 1) n = 3584
| Baseline predictors | Group 2 | Group 3 | Group 4 |
|---|---|---|---|
| Age (per 5-year increase) | 0.90 (0.85, 0.95) | 0.82 (0.77, 0.88) | 0.71 (0.64, 0.79) |
| Sex (women vs. men) | 0.97 (0.80, 1.16) | 0.70 (0.56, 0.88) | 0.64 (0.46, 0.90) |
| BMI | |||
| overweight vs. normal | 1.23 (0.99, 1.53) | 1.40 (1.05, 1.89) | 1.58 (0.94, 2.65) |
| obese vs. normal | 1.32 (1.03, 1.68) | 1.50 (1.10, 2.06) | 1.95 (1.17, 3.25) |
| Widespread pain (yes vs. no) | 1.85 (1.35, 2.56) | 2.30 (1.60, 3.29) | 2.48 (1.59, 3.85) |
| Pain in other body regions | |||
| Back pain (yes vs. no) | 1.58 (1.31, 1.89) | 1.39 (1.10, 1.77) | 2.16 (1.47, 3.17) |
| Hip pain (yes vs. no) | 1.35 (1.08, 1.70) | 1.56 (1.19, 2.04) | 1.60 (1.11, 2.31) |
| Ankle pain (yes vs. no) | 1.48 (1.15, 1.90) | 1.86 (1.39, 2.48) | 2.32 (1.60, 3.38) |
| Pain medication use (yes vs. no) | 2.49 (2.05, 3.04) | 4.01 (3.15, 5.09) | 6.26 (4.25, 9.23) |
| WOMACa stiffness (per unit increase) | 1.70 (1.57, 1.83) | 2.03 (1.87, 2.22) | 3.11 (2.76, 3.51) |
| Depressive symptoms (yes vs. no) | 1.60 (1.15, 2.23) | 1.48 (1.003, 2.19) | 2.82 (1.79, 4.43) |
| Comorbidity (≥ vs. < 2) | 1.20 (0.90, 1.59) | 1.22 (0.86, 1.75) | 2.21 (1.41, 3.44) |
| Gait speed (per 0.1 m/s increase) | 0.96 (0.92, 1.01) | 0.95 (0.90, 1.01) | 0.77 (0.71, 0.84) |
| K/L grade | |||
| 1 vs. 0 | 0.91 (0.70, 1.18) | 0.94 (0.66, 1.33) | 0.82 (0.46, 1.47) |
| 2 vs. 0 | 1.23 (0.97, 1.55) | 1.38 (1.02, 1.87) | 1.11 (0.69, 1.78) |
| 3&4 vs. 0 | 1.70 (1.31, 2.21) | 2.22 (1.60, 3.06) | 2.32 (1.44, 3.74) |
Bold fonts indicate statistically significant odds ratio with associated 95% confidence interval that excludes 1.0.
a
WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), high scores indicate worse status.
Group 1: minimal intermittent pain and no constant pain
Group 2: mild intermittent pain and no constant pain
Group 3: mild intermittent pain and low-grade constant pain
Group 4: moderate constant pain and moderate intermittent pain