Predictors of fatigue and persistent fatigue in early rheumatoid arthritis: a longitudinal observational study, data from the ESPOIR cohort.

Objective: To determine, in a cohort of patients with early rheumatoid arthritis (RA), factors associated with fatigue at baseline, describe its evolution over 5 years of follow-up, and determine baseline predictors of persistent fatigue.

Method: We selected patients fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism criteria for RA included in the ESPOIR cohort. Using bivariable and multivariable logistic regression models, we examined baseline variables associated with baseline fatigue (defined by visual analogue scale fatigue > 20) and baseline predictors of persistent fatigue (if the patient experienced fatigue at all visits during the 5 year follow-up period).

Results: We analysed 673 patients; 80.7% reported fatigue at baseline. At baseline, fatigue was associated with female gender, younger age, greater severity of morning stiffness, sleep problems, higher Health Assessment Questionnaire levels, presence of sicca symptoms, history of thyroid problems, and presence of psychological distress (depressive or anxiety symptoms). At 5 years of follow-up, the percentage of fatigued patients who reported fatigue at all time-points since baseline was 24.6% (referred to as 'persistent fatigue'). Independent baseline predictors were presence of sicca symptoms, greater severity of morning stiffness, and psychological distress.

Conclusions: Fatigue is a frequent symptom in RA. The presence of sicca symptoms, greater severity of morning stiffness, and presence of psychological distress at baseline were associated with baseline fatigue and persistent fatigue at 5 years. We did not observe any association between baseline fatigue or persistent fatigue and the Disease Activity Score based on 28-joint count-erythrocyte sedimentation rate.