[The characteristics and associated factors of hand dysfunction in patients with rheumatoid arthritis]

Objective: To investigate the characteristics of hand dysfunction and its associated factors in patients with rheumatoid arthritis (RA). Methods: A cross-sectional study. Patients with RA were recruited from January 2019 to April 2024 at the Department of Rheumatology and Immunology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. Demographic and clinical data were collected, including age, gender, active smoking, disease duration, time of morning stiffness, rheumatoid factor and anti-cyclic citrullinated peptide antibody, disease activity, radiographic indicators, and hand function assessment. Hand function was assessed by grip strength measures and self-reported items related to hand function in the Stanford Health Assessment Questionnaire. Factors related to hand function were analyzed by logistic regression analyses. Results: A total of 1 079 RA patients were recruited [mean age: (53.0±12.6) years]. Overall, 72.6% (783/1 079) patients experienced a decrease in grip strength, 57.2% (617/1 079) patients experienced a decreased grip strength in both hands, with the average grip strength of the left and right hands decreasing by 16.3% and 14.1%, respectively, compared to normal values; 39.9% (430/1 079) patients had self-reported hand dysfunction. There were 185 (17.1%) older RA patients (age ≥65 years). The proportion of older RA patients with decreased grip strength [89.7% (166/185) vs. 69.0% (617/894)] and degree of decrease in grip strength compared to normal values (left hand:-35.3%±30.6% vs. -12.3%±38.6%; right hand:-32.6%±32.3% vs. -10.3%±42.1%) were significantly higher than that in young patients, and the proportion of older patients with self-reported hand dysfunction was also significantly higher [53.0% (98/185) vs. 37.1% (332/894), all P<0.001]. Multivariate logistic regression analysis showed that pain visual analogue scale (OR=1.375, 95%CI 1.020-1.854) was independently associated with grip strength decrease in older RA patients, while the 28-joint tender joint count (OR=1.151, 95%CI 1.063-1.246) and provider global assessment of disease activity (OR=1.381, 95%CI 1.171-1.628) were associated with self-reported hand dysfunction. Conclusions: Hand dysfunction is common in RA patients, especially among older RA patients, which is related to pain, joint tenderness and provider global assessment of disease activity. This result implies the importance of pain management in RA patients.