Fatigue In Psoriatic Arthritis Is Related To Disease Activity Rather Than To Demographic Characteristics - An Ancillary Analysis Of The Cross-Sectional International Psaid Study Of 246 Patients

Background Fatigue is an important aspect of disease for people suffering from psoriatic arthritis (PsA) (ref 1). However, little is known about the factors explaining fatigue in PsA. The causes of fatigue in inflammatory rheumatic diseases such as PsA, spondyloarthritis or rheumatoid arthritis are unclear; fatigue is diversely reported as being related either to patient characteristics, e.g., demographic, psychological and social factors, or to disease characteristics, e.g. disease activity. Objectives To evaluate the magnitude of fatigue in PsA and to assess if fatigue appears more strongly associated with patient- or with disease-related characteristics. Methods Patients: international cross-sectional study of unselected patients with a definite diagnosis of PsA according to the CASPAR criteria, in 13 countries [1]. Magnitude of fatigue was assessed by a numeric rating scale (range 0-10). Factors associated with high fatigue (>5/10) were assessed by multivariate logistic regression. The factors tested for association were patient related characteristics including demographic variables (age, gender, disease duration and country, education level); disease-related characteristics including articular activity (number of tender joints and number of swollen joints), skin activity (current psoriasis of more than 5% body surface); other activity (axial involvement, enthesitis, dactylitis, extra-articular involvement) and structural damage. Other patient reported outcomes including quality of life were not analysed since usually highly associated to fatigue. Results Data from 246 patients were analysed: mean age 51.2±13.0 yrs; N=119 (48.8%) males. Most had long-standing disease. Mean (±SD) fatigue was 5.0 (±3.0); 44.7% of patients had a fatigue level above 5 out of 10. High fatigue was well explained (AUC of the model, 0.73) by the following elements in multivariate analysis: higher skin activity (odds ratio, OR=4.7 [1.1; 20.7]), higher tender joint count (OR=1.1 [1.0; 1.1]) and lower education level (OR=0.9 [0.8; 1.0]). Conclusions Fatigue levels were high in this population of patients with PsA. High fatigue was explained mainly by disease activity rather than patient-related variables, indicating fatigue may be closely related to the disease process in PsA. Further studies are needed. References Gossec et al. PsAID study, EULAR 2013. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.2309