Trends in fatigue in inflammatory rheumatic diseases: Annual data and trajectory analysis of the German National Database 2007-2023

Abstract

Objective: To explore the development of fatigue over the past 17 years and its relationship to physician- and patient-reported outcomes and social factors in inflammatory rheumatic diseases.

Methodology: Data from ≈9300 patients per year from the German National Database (2007-2023) were included, considering arthritides, spondyloarthritides, connective tissue diseases and vasculitides. Fatigue was assessed on a numeric rating scale (0-10) with >2 defined as present and >6 as severe. Presence and severity were compared by diagnosis, gender and year. Fatigue clusters were identified based on trajectory patterns over three consecutive visits.

Results: Fatigue affected 55 % (adult onset Still disease) to 67 % (systemic sclerosis) of patients, with severe fatigue in up to 26 % (systemic sclerosis). Substantial proportions of women (47-61 %) and men (35-52 %) experienced moderate-to-severe fatigue. Despite marked improvements in inflammation-responsive outcomes (CRP -40 %, tender joints -50 %, physician disease activity -42 %) and employment (52 %→70 %), mean fatigue remained stable. Trajectory analysis identified 35 % with persistent low, 23 % persistent high, 24 % worsening, and 19 % improving fatigue. Tender joints and morning stiffness effectively discriminated between persistent high versus low fatigue clusters. Emotional well-being, physical functioning, coping, and sleep quality showed stronger associations with fatigue trajectories than inflammatory markers. Differences across fatigue clusters substantially exceeded those between diagnostic groups.

Conclusion: Fatigue affected a large proportion of both women and men across diagnoses. Fatigue trajectories reflect complex interplay of clinical and psychosocial factors. Management should incorporate multidimensional interventions addressing emotional well-being, physical function and social support beyond traditional inflammatory control.

Keywords: Axial spondyloarthritis; Fatigue; Rheumatoid arthritis; Sjoegren’s syndrome; Systemic lupus erythematosus; Systemic sclerosis.