This study aims to describe the association between sociodemographic factors and trajectories of disease, disability and health-related quality of life (HRQoL) in early rheumatoid arthritis (ERA).
Data were collected prospectively over 3 years in the Singapore Early Arthritis Cohort study. Trajectories were modeled using multi-trajectory group-based trajectory modeling (GBTM) and determinants of trajectory membership were identified using multinomial logistic regression.
Two hundred and thirteen patients were included: 58.2% Chinese, 16.4% Malay, 21.6% Indian, mean (SD) age 51.3 (12.6) years and symptom duration 21.8 (15.3) weeks. In the multi-trajectory analysis, three groups of disease trajectories and corresponding disability and HRQoL trajectories were identified: group 1 (moderate disease rapid response, 49.9%), group 2 (high disease rapid response, 31.1%) and group 3 (high disease slow response, 19.1%). Malay patients had higher relative risk ratio (RRR) of being in trajectory groups 2 and 3 compared to group 1 (RRR = 2.30, 95% CI 1.05-3.98 and RRR = 4.02, 95% CI 1.45-6.43, respectively) while patients with tertiary education had lower relative risk (RRR = 0.56, 95% CI 0.45-0.89 and RRR = 0.33, (95% CI 0.14-0.83, respectively). In the analysis of individual outcomes, ethnicity, education level and body mass index were determinants of the heterogeneous disease activity trajectories. Gender and education level were determinants of the disability trajectories. Only gender was a determinant of the HRQoL trajectories. Further, 96.2% of the patients were treated with conventional synthetic disease-modifying antirheumatic drugs.
Disparities in sociodemographic factors should be taken into consideration in formulating treatment strategies in ERA.