Fatigue severity at disease onset in relation to clinical variables at disease onset in rheumatoid arthritis
| Effect size in mm (SE) | p Value | |
|---|---|---|
| Univariable analyses | ||
| Female | 7.1 (3.4) | 0.040* |
| Age at onset, per year | −0.004 (0.1) | 0.95 |
| Symptom duration, per week | 0.1 (0.02) | <0.001* |
| Morning stiffness duration, per minute | 0.04 (0.01) | <0.001* |
| SJC, per joint | 0.4 (0.2) | 0.010* |
| TJC, per joint | 1.4 (0.2) | <0.001* |
| CRP, per mg/L | 0.1 (0.05) | 0.072 |
| Hb, per mmol/L | −3.6 (1.2) | 0.002* |
| ACPA-positivity | −4.3 (3.0) | 0.15 |
| RF-positivity | −0.3 (2.4) | 0.90 |
| SHS, per point | 0.02 (0.2) | 0.93 |
| Multivariable analysis | ||
| Female | 7.6 (2.3) | 0.001* |
| Age at onset, per year | −0.01 (0.1) | 0.20 |
| Symptom duration, per week | 0.1 (0.02) | <0.001* |
| Morning stiffness duration, per minute | 0.03 (0.01) | 0.002* |
| SJC, per joint | −0.3 (0.2) | 0.071 |
| TJC, per joint | 1.1 (0.2) | <0.001* |
| CRP, per mg/L | 0.1 (0.03) | 0.096 |
| Hb, per mmol/L | −0.9 (1.5) | 0.54 |
| ACPA-positivity | −7.9 (2.6) | 0.003* |
| RF-positivity | 3.8 (2.7) | 0.15 |
*p<0.05.
Presented are the results of the analyses on 902 patients with RA with fatigue severity at disease onset as outcome and the other variable at disease onset as independent variable. Variables with p values <0.05 in univariable analyses and clinically relevant variables were included in multivariable analysis. The effect sizes indicate how much the fatigue severity at disease onset on a 0–100 mm scale changed with 1 unit increase in the other variable at disease onset. For example, women have a 7.1 mm higher fatigue severity at baseline compared to men and the fatigue severity measured at disease onset increased 1.4 mm per tender joint.
ACPA, anticitrullinated peptide antibodies; CRP, C reactive protein; Hb, haemoglobin; RA, rheumatoid arthritis; RF, IgM rheumatoid factor; SHS, Sharp-van der Heijde score; SJC, 66-swollen joint count; TJC, 68-tender joint count.