Interpretation of 28-Joint Disease Activity Score and its Components in the Assessment of Inflammatory and Non-Inflammatory Aspects of Rheumatoid Arthritis

Abstract

Background: The 28-joint DAS with ESR (DAS28-ESR) is used as a measure of inflammatory disease activity in RA. However, pain and non-inflammatory mechanisms (e.g. central sensitisation) might confound the DAS28 by modulating the visual analogue scale for general health (VAS-GH) and tender joint count (TJC). Several transformations have rearranged the DAS28 formula in an attempt to measure non-inflammatory pain contributions in RA. We aimed to compare different DAS28 components and these derived measures to assess their utility in the analysis of non-inflammatory factors and to inform interpretation of the DAS28 as an index of RA inflammatory disease activity.