THU0100 FATIGUE: A PREVALENT AND PERSISTENT SYMPTOM IN EARLY RHEUMATOID ATHRITIS
Authors: O. Ifesemen, D. Mcwilliams, A. Young, P. Kiely, D. Walsh
Journal: Annals of the Rheumatic Diseases (2020)

Background: Fatigue is associated with poor quality of life in people with Rheumatoid Arthritis (RA). The exact burden of fatigue in RA is uncertain. Evidence shows that fatigue may persist, even in people with well-controlled inflammatory disease. However, this is largely based on cross sectional data, and data from people with long standing or refractory disease. This study aims to examine the nature of fatigue in early RA. Objectives: Describe the prevalence of fatigue and longitudinal course of fatigue Investigate heterogeneity in the course of fatigue and identify risk factors associated with fatigue heterogeneity Methods: Data were from the early Rheumatoid Arthritis Network (ERAN), an inception cohort of people with a disease duration of &lt;24mths, recruited from 2002-11 (n=1236). ERAN collected demographic, clinical, quality of life, comorbidities and laboratory data at baseline, 3-6 mths, and then annually. Fatigue was measured using the Vitality subscale of the Short Form Health Survey questionnaire (SF36VT). Fatigue and severe fatigue were classified as SF36VT values lower than 1 and 2 standard deviations (SD) below the UK healthy population average respectively. Baseline prevalence rates standardized to Eurostat 2013 by age and sex were calculated. The course of fatigue was examined using linear mixed effect models. Group Based Trajectory Modelling (GBTM) was used to examine heterogeneity in the course of fatigue. Baseline characteristics were then used to identify predictors of group membership using univariate and multiple regression analysis. Results: Baseline characteristics include female sex (67%), mean age = 57(SD±14) yrs. Mean SF36VT score = 41(SD±11), median disease duration was 11 mths (IQR:7 – 18). The age and sex standardized prevalence rates of fatigue and severe fatigue were 44%(CI:38-50) and 18% (CI:15 – 22) respectively. 729 (59%) participants were included in the longitudinal analysis. Over the course 4 years follow up, and after accounting for the effect of age, sex, patient’s global assessment of disease activity, BMI, pain and mental health, there was a reduction in the population vitality levels from baseline,(β: -0.14CI: -0.26 to -0.02, p ≤ 0.001). Inflammation measured by erythrocyte sedimentation rate (ESR) was not significantly associated with the course of fatigue. GBTM analysis identified 2 sub-groups. These groups were named ‘Fatigue’ and ‘No-fatigue’ groups and comprised about 52% and 47% of the population respectively (Fig 1). Females, participants with, at baseline, higher BMI, higher disability score (HAQ), disease activity score (DAS28), worse pain, mental health scores and higher comorbidity score (RDCI) were more likely to belong to the Fatigue group (each p ≤ 0.05) in univariate analysis. However, higher BMI (OR 1.05 (CI: 1.0 – 1.1), HAQ (OR 2: CI: 1.5 - 2.7), RDCI(OR 1.3, CI: 1.2 – 1.5), worse SF36 pain and mental health scores (OR 0.93 CI: 0.92 – 0.95) and (OR 0.97, CI: 0.95 – 0.99) were collectively associated with fatigue group membership (AUROC=0.81). Fig 1. Fatigue Trajectories Conclusion: Fatigue is a prevalent symptom in RA, even in early disease. Embedded within the RA population are distinct sub-populations, with or without fatigue. Those with fatigue at baseline were likely to continue to report fatigue over 4 years of follow up. Unlike our previous data on pain trajectories within this cohort, a ‘resolving fatigue’ was not found. Diverse baseline characteristics, including pain, were associated with persistent fatigue. Management of fatigue might require strategies additional to disease modification, and people who require such interventions might be identified at presentation with early RA. Disclosure of Interests: Onosi Ifesemen: None declared, Daniel McWilliams Grant/research support from: Grant support from Pfizer Ltd, Adam Young: None declared, Patrick Kiely: None declared, David Walsh Grant/research support from: Grant support from Pfizer Ltd and Eli Lilly, Consultant of: Consultancy to Eli Lilly, Pfizer, Abbvie and GSK (all payments made to University of Nottingham). Consultancy to Love Productions(all payments made to the University of Nottingham).