Drs. Behrens and Tony and Drs. Greger and Burkhardt contributed equally to this work.
Development and Validation of a New Disease Activity Score in 28 Joints–Based Treatment Response Criterion for Rheumatoid Arthritis
Article first published online: 24 SEP 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis Care & Research
Volume 65, Issue 10, pages 1608–1616, October 2013
How to Cite
Behrens, F., Tony, H.-P., Alten, R., Kleinert, S., Scharbatke, E. C., Köhm, M., Gnann, H., Tams, J., Greger, G. and Burkhardt, H. (2013), Development and Validation of a New Disease Activity Score in 28 Joints–Based Treatment Response Criterion for Rheumatoid Arthritis. Arthritis Care Res, 65: 1608–1616. doi: 10.1002/acr.22037
- Issue published online: 24 SEP 2013
- Article first published online: 24 SEP 2013
- Accepted manuscript online: 22 APR 2013 03:43PM EST
- Manuscript Accepted: 12 APR 2013
- Manuscript Received: 4 OCT 2012
- AbbVie Deutschland GmbH & Co. KG (prior sponsor Abbott GmbH & Co. KG)
To define a valid criterion for treatment response as assessed by the Disease Activity Score in 28 joints (DAS28) that exceeds random disease activity variations in patients with rheumatoid arthritis (RA).
We utilized anonymized data sets of RA patients from multiple rheumatology centers in Germany to identify patients with stable responses to conventional or biologic disease-modifying antirheumatic drug (DMARD) therapy (discovery cohort). To evaluate fluctuations in DAS28 scores, we subjected patients' DAS28 scores at months 12, 18, and 24 to an analysis of variance model to establish a 1-sided 95% confidence interval for normal fluctuations; this value was used to define the critical difference (DAS28-dcrit) for individual changes from baseline. The DAS28-dcrit value was then applied to analyses of therapeutic response in an adalimumab noninterventional study cohort.
The discovery cohort included 415 patients receiving stable treatment. Values for DAS28-dcrit were comparable regardless of age, sex, disease activity, and class of therapy (DMARDs or biologic agents) and fell below 1.8 in all subgroups. We therefore conclude that DAS28 improvements of 1.8 or higher are outside the normal variation and represent a therapeutic response. When applied to data from the adalimumab noninterventional study (n = 1,874), a DAS28-dcrit response was more robust over time than a European League Against Rheumatism response and was more closely correlated with improved functional capacity.
Based on our data, a DAS28-dcrit value of 1.8 signifies a positive individual therapeutic response that exceeds the threshold of random fluctuation. The DAS28-dcrit criterion may be useful in steering individual therapy and stratifying clinical trials.