This study aimed to assess the clinical features as well as the functional and psychological status of patients with rheumatoid arthritis and fibromyalgia in a real-world setting in China.
A total of 202 inpatients with rheumatoid arthritis from the Department of Rheumatology and Immunology at Peking University People’s Hospital were enrolled between December 2018 and April 2019. These inpatients were assessed for the presence of fibromyalgia using the 1990 American College of Rheumatology’s classification criteria for fibromyalgia. Disease activity and functional and psychological status were assessed using the Disease Activity Score in 28 Joints (DAS-28), Short Form-36 health survey questionnaire (SF-36), Health Assessment Questionnaire (HAQ), Hospital Anxiety and Depression Scale, and Visual Analog Scale.
Of 202 patients with rheumatoid arthritis, 42 (20.8%) had concurrent fibromyalgia. Compared to patients without fibromyalgia, those with rheumatoid arthritis and fibromyalgia had higher DAS-28 scores (6.0 vs. 4.4, P=0.011) and notably higher tender joint counts (16.5 vs. 4.5, P<0.001). Patients with rheumatoid arthritis and fibromyalgia had worse HAQ scores (1.24 vs. 0.66, P<0.001) and lower SF-36 scores (28.6 vs. 58.2, P<0.001). Additionally, patients with rheumatoid arthritis and fibromyalgia experienced more fatigue (88.1% vs. 50.6%, P<0.001) and had higher anxiety (10 vs. 4, P<0.001) and depression scores (12 vs. 6, P<0.001). No significant differences in erythrocyte sedimentation rate, C-reactive protein concentration, morning stiffness period, or swollen joint counts were identified between the groups.
Patients with rheumatoid arthritis and fibromyalgia had higher disease activity, worse functional and psychological status, and poorer quality of life. DAS-28 scores may have been overestimated in these patients. When patients with rheumatoid arthritis do not achieve remission, the possibility of fibromyalgia should be considered.