A Cross-Sectional Study of the Relationship Between Disease Activity and Fatigue in Rheumatoid Arthritis Patients at King Abdulaziz University Hospital, Saudi Arabia.

BACKGROUND

Fatigue is one of the most prevalent and disabling symptoms in patients with rheumatoid arthritis (RA), yet its relationship with disease activity remains complex and underexplored in many populations.

OBJECTIVE

To evaluate the association between disease activity and fatigue in RA patients at King Abdulaziz University Hospital using validated clinical measures.

METHODS

A cross-sectional study was conducted among 253 RA patients fulfilling the ACR/EULAR 2010 classification criteria. Disease activity was assessed using the Clinical Disease Activity Index (CDAI), and fatigue was measured with the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale. Relationships between fatigue (FACIT-F scores) and CDAI were examined using Pearson correlation with continuous CDAI scores. Descriptive statistics (mean ± SD) of FACIT-F scores across CDAI categories were provided for illustration. Multivariate linear regression adjusted for age, sex, disease duration, body mass index, employment status, serological markers, and treatment type. ANOVA was applied to assess differences in mean FACIT-F scores across disease activity categories. Statistical significance was set at p < 0.05.

RESULTS

Fatigue was reported by 80% of patients, with 10% experiencing severe fatigue (FACIT-F ≤13). Mean FACIT-F scores decreased as disease activity increased: remission 40.1 ± 8.2, low disease activity 35.7 ± 10.4, moderate disease activity 25.6 ± 9.8, and high disease activity 15.4 ± 7.3 (p < 0.001, ANOVA). Pearson correlation demonstrated a strong inverse relationship between CDAI and FACIT-F scores (r = -0.68, 95% CI: -0.83 to -0.45 in the high disease activity group). Multivariate analysis confirmed that disease activity remained a key determinant of fatigue after adjusting for potential confounders, with female sex, obesity, and longer disease duration also independently associated with lower FACIT-F scores.

CONCLUSION

Fatigue in RA is strongly associated with disease activity but persists in patients with well-controlled inflammation, reflecting multifactorial origins. Routine fatigue assessment and holistic management strategies addressing both inflammatory and non-inflammatory contributors are essential to improve patient quality of life and treatment outcomes.