Factors associated with quality of life and functional disability among rheumatoid arthritis patients treated with disease‐modifying anti‐rheumatic drugs for at least 6 months

Aim To determine characteristics of rheumatoid arthritis (RA) patients in Korea using disease‐modifying anti‐rheumatic drugs (DMARDs) for at least 6 months, and to identify factors associated with poor health‐related outcomes. Method A total of 2000 RA patients aged > 20 years, treated with DMARDs for at least 6 months, and signed informed consent, were enrolled in this non‐interventional, multicenter, cross‐sectional observational study from December 2012 to June 2013. Health‐related quality of life (HRQoL) was measured using EuroQuol 5D (EQ‐5D) and functional disability was measured using the Korean Health Assessment Questionnaire (KHAQ). Univariate and multivariate linear regression analyses were used to determine the association between patient characteristics and patient‐reported outcomes (PROs). Results Of all RA patients, 84% were female, patients with low Disease Activity Score of 28 joints erythrocyte sedimentation rate (DAS‐28‐ESR < 3.2) was 54%, while moderate (DAS‐28‐ESR 3.2–5.1) and high disease activity score (DAS‐28‐ESR > 5.1) were 38% and 7.6%, respectively. Mean EQ‐5D index score and KHAQ score were 0.6 ± 0.28 and 0.7 ± 0.67, respectively. In multivariate analysis with both PROs, average HRQoL and functional disability score appeared to be worse in persons with older age compared to younger age (P < 0.001), and worse in females compared to males (P < 0.001). Compared to patients having lower DAS (< 3.2), those with moderate and highest DAS (3.2–5.1 and > 5.1) had worse outcome measures (P < 0.001). Conclusion In this study, higher DAS was one of the most influential factors for poor PROs among all other factors. Therefore, we could suggest appropriate treatment approaches according to DAS along with other significantly associated factors with PROs in the early stage of RA.