To investigate the effect of bilateral and unilateral joint disease on the Modified Health Assessment Questionnaire (MHAQ) scores and the differences in joint weighting in rheumatoid arthritis patients.
A total of 9212 subjects from the Japanese nationwide cohort database NinJa, 2011, were analyzed. The presence or absence of disease in each joint, including swelling and/or tenderness, was investigated. The correlations between bilateral and unilateral disease in each joint and MHAQ scores were investigated using multivariable logistic regression analysis.
The patients' mean age and disease duration was 63.2 and 12.2 years, respectively. The Disease Activity Score-28 was 3.3. The odds ratios of physical impairment according to the MHAQ using multivariable logistic regression models for bilateral and unilateral joints, respectively, were: shoulder, 4.0 and 1.8; elbow, 2.6 and 1.8; wrist, 1.9 and 1.5; hip, 1.7 and 3.0; knee, 2.6 and 1.9; ankle, 2.3 and 2.0, finger, 1.4 and 1.2; and toe, 1.0 and 1.1. The shoulder, elbow, wrist, knee, and ankle had a significant effect on physical impairment.
The MHAQ score was significantly affected by shoulder, elbow, wrist, knee, and ankle joint disease. Furthermore, bilateral disease tended to have a greater effect on physical impairment than unilateral disease.