Background Some patients with rheumatoid arthritis (RA) do not respond adequately to treatment.
Objectives We investigated the contributions made by the subjective components of the disease activity score 28 (DAS28) to the treatment response of RA. In addition, factors associated with poor response to treatment at 6 months, despite normalization of objective measures, were examined.
Methods A total of 426 newly diagnosed RA patients treated from August 2011 to December 2014 were included. The DAS28-P score (the subjective components of the DAS28 relative to the total components) was calculated as DAS28-P = 0.56*sqrt(TJC28) + 0.014*(VAS-GH) / 0.56*sqrt(TJC28) + 0.28*sqrt(SJC28) + 0.78In(ESR) + 0.014*(VAS-GH). The EULAR response was assessed after 6 months of treatment. Of those who failed to attain good EULAR responses, those for whom the objective measures (the ESR, the CRP level, and swollen joints) were normalized were defined as having failed treatment because of subjective measures.
Results The mean age of all patients was 54 years and 79% were female. The median (IQR) DAS28 score at baseline was 4.8 (4.04–5.49) and that after 6 months of treatment 3.21 (2.41–3.95). Good responders (according to the EULAR criteria) numbered 180 (38.9%), moderate responders 150 (32.4%), and non-responders 96 (20.7%). The DAS28-P score fell significantly from baseline to 6 months in good (0.43 versus 0.28, p<0.001) and moderate responders (0.44 versus 0.4, p=0.003), but not in non-responders (0.43 versus 0.45, p=0.727). Younger age, a lower DAS28 score, and a lower DAS28-P score at baseline were related to a good EULAR response. Subjects who failed to respond because of subjective measures tended to have higher DAS28-P scores at baseline.
Conclusions We found that RA patients with high DAS28-P scores, reflecting subjective measures, were less likely to achieve good EULAR responses 6 months after treatment initiation and tended not to be classified as good responders despite normalization of objective measures.
Disclosure of Interest None declared