Table 3

Fatigue severity over 8 years in relation to the course of inflammation and other variables in rheumatoid arthritis

Effect size in mm (SE)p Value
Univariable analyses
 Female6.1 (1.7)<0.001*
 Age at disease onset, per year−0.2 (0.1)0.043*
 SJC, per joint0.7 (0.1)<0.001*
 TJC, per joint1.1 (0.1)<0.001*
 CRP, per mg/L0.1 (0.03)<0.001*
 Hb, per mmol/L−3.6 (1.2)0.003*
 ACPA-positivity−0.5 (2.0)0.79
 RF-positivity−3.3 (1.7)0.053
 SHS, per point−0.1 (0.1)0.14
Multivariable analysis
 Female4.4 (1.9)0.022*
 Age at disease onset, per year−0.2 (0.1)0.016*
 SJC, per joint0.3 (0.1)0.022*
 TJC, per joint1.0 (0.1)<0.001*
 CRP, per mg/L0.1 (0.04)0.049*
 Hb, per mmol/L−0.9 (1.1)0.38
 ACPA-positivity0.4 (2.1)0.84
 RF-positivity−1.9 (2.1)0.36

  • Presented are the results of the longitudinal analyses in 626 patients with RA. Variables with p values <0.05 in univariable analysis and clinically relevant variables were included in multivariable analysis. The outcome (fatigue) and the clinical variables SJC, TJC, CRP, Hb and SHS were measured yearly. Gender, age, RF and ACPA were determined at disease onset. The effect sizes indicate how much the fatigue on a 0–100 mm scale change with 1 unit increase in the other variable. For example, 1 mg/L increase in CRP is associated with a 0.1 mm increase in fatigue severity measured at the same time point during 8 years follow-up and women have a 6.1 mm higher fatigue score at every time point over 8 years than men.

  • 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.