An Observational Study on Assessment of Disease Activity in Rheumatoid Arthritis Patients Using Patient-Based Disease Activity Score 2 (PDAS-2)

To assess the utility of Patient-Based Disease Activity Score 2 (PDAS-2) in assessing the disease activity in rheumatoid arthritis (RA). A prospective cohort study was conducted on 80 patients of RA. The demographic and clinical characteristics of the patients were recorded. They were assessed for disease activity using “Disease Activity Score 28” (DAS-28), “Clinical Disease Activity Index” (CDAI), and PDAS-2 score at baseline (M0), at 2 months (M2), and at 4 months (M4) while they were on treatment. Data were analyzed for correlation of PDAS-2 with other scores and internal reliability. p <0.05 was considered for statistical significance. The mean age was 40.13 ± 11.74 years with 70 females and 10 males. There was significant reduction in DAS-28, CDAI, and PDAS-2 score over 4-month follow-up (all scores’ p values <0.001). Internal reliability (as assessed by Cronbach’s alpha) of PDAS-2 was 0.578. PDAS-2 showed significant correlation with DAS-28 at M0, M2, and M4 ( r =0.792, 0.757, and 0.669 respectively, p value <0.001) and CDAI ( r =0.861, 0.832, and 0.695 respectively, p value <0.001). Overall there was a significant agreement between DAS-28 and PDAS-2 ( K =0.788, p <0.001) and between CDAI and PDAS-2 ( K =0.766, p <0.001). PDAS-2 score can be routinely used in clinical practice owing to its correlation with DAS-28/CDAI and because of the advantage that it assessed the patients’ daily living activities.