Statistics from Altmetric.com
Early treatment initiation is crucial to improve long-term outcomes in rheumatoid arthritis (RA). This may also apply to undifferentiated arthritis (UA), patients at high risk of persistent arthritis/RA. Therefore, the EULAR recommendations for early arthritis recommend assessing the following risk factors for disease persistency in early UA: number of swollen joints, acute phase reactants (ie, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)), rheumatoid-factor (RF), anti-citrullinated protein antibodies (ACPA) and imaging findings/erosions.1 2 This recommendation was based on markers identified as predictive in a systematic literature review.2 Importantly however, prognostic research in UA is based on an outdated definition of UA: not meeting 1987-RA-classification criteria and having no alternative diagnosis (‘conventional UA’). A proportion of these patients with conventional UA meet the 2010-RA-criteria and is currently considered to have RA.3–5 Contemporary UA, in contrast, is defined as neither meeting the 1987-RA-criteria nor the 2010-RA-criteria and having no other clinical diagnosis. In addition, for some of the recommended risk factors data were lacking in the systematic literature review (polyarthritis) or it was concluded that adequately designed studies were lacking (CRP and ESR).2 Since predictors may be disease stage or population dependent, and because predictors for persistent disease identified in conventional UA may not be applicable to contemporary UA, we conducted a large cohort study in contemporary UA to assess risk factors …
Handling editor Josef S Smolen
Contributors All authors contributed to the conception and study design. NKdH contributed to acquisition of the data and analysed the data. All authors contributed to interpretation of the data and the development of the manuscript. All authors approved the final version of the manuscript.
Funding The research leading to these results has received funding from the Dutch Arthritis Foundation and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (starting grant, agreement No 714312).
Disclaimer The funding source had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; or decision to submit the manuscript for publication.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.