Baseline characteristic/factor RR (95% CI) | Pain trajectory groups | ||||
---|---|---|---|---|---|
C (moderate regression) | E (major regression) | B (severe progression) | D (moderate progression) | F (constant severe) | |
n = 207 | n = 23 | n = 35 | n = 180 | n = 74 | |
BMI | 1.06 (1.00 to 1.13) | 0.96 (0.85 to 1.10) | 1.07 (0.96 to 1.19) | 1.09 (1.02 to 1.16)b | 1.10 (1.01 to 1.20)b |
Highest achieved education level | |||||
Primary or secondary school | ref | ref | ref | ref | ref |
University/college | 0.53 (0.32 to 0.87)b | 0.83 (0.27 to 2.51) | 0.33 (0.16 to 0.95)b | 0.44 (0.24 to 0.80)b | 0.55 (0.23 to1.31) |
>1 comorbidity | 1.75 (1.10 to 2.77)b | 1.37 (0.48 to 3.85) | 2.87 (1.23 to 6.67)b | 1.23 (0.74 to 2.08) | 2.65 (1.25 to 6.99)b |
WOMAC physical function subscalec | 1.04 (1.02 to 1.06)b | 1.13 (1.09 to 1.17)b | 1.01 (0.98 to 1.05) | 1.09 (1.07 to 1.12)b | 1.14 (1.11 to 1.18)b |
Knee joint space tenderness | 1.70 (1.07 to 2.69)b | 2.13 (0.76 to 6.02) | 2.84 (1.21 to 6.67)b | 3.86 (2.28 to 6.62)b | 2.03 (0.96 to 4.33) |
Painful flexion knee | 0.91 (0.56 to 1.49) | 0.14 (0.03 to 0.69)b | 0.90 (0.37 to 2.19) | 0.77 (0.44 to 1.33) | 1.08 (0.51 to 2.29) |
↵a Relative to reference trajectory (constant mild, group A), n = 186.
↵b P<0.05.
↵c RR per unit increase. A higher WOMAC score indicates more limitations due to physical health. BMI = body mass index. RR = relative risk ratio (obtained by multinomial logistic regression, adjusted for age and sex. Nagelkerke R2 = 0.42 for the model). WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index.