Background Recently a European League Against Rheumatology (EULAR)-taskforce has defined arthralgia suspicious for progression to rheumatoid arthritis (RA)¹, in order to allow inclusion of homogeneous sets of arthralgia patients in clinical studies. This was done as the field is currently shifting towards performing trials in very early disease phases as there is growing evidence that very early treatment initiation allows better disease modification and treatment of arthralgia may even prevent the development of RA. The definition was developed with the clinical expertise as reference. It is intended for use in arthralgia patient that rheumatologists' consider to be at risk for progression to RA

Objectives To longitudinally evaluate the EULAR definition of arthralgia suspicious for progression to RA in: (1) patients in whom rheumatologists felt that imminent RA was more likely than other arthralgia's (Clinically Suspect Arthralgia, CSA); this target population fulfils the entry criterion and (2) in arthralgia patients referred to secondary care prior to rheumatologic evaluation; in these patients the entry criterion was ignored.

Methods The definition was assessed in 241 Dutch CSA-patients and 113 patients referred to the Umeå university hospital with recent-onset arthralgia in small joints. The external reference was arthritis development <2-years follow-up.

Results CSA-patients with a positive definition (≥3/7 parameters present) had an increased risk on arthritis development compared to definition-negative CSA-patients (HR 2.1, 95% CI 0.9–4.7). The sensitivity of a positive definition was 84% and the positive predictive value (PPV) 30%. In arthralgia patients in whom the definition was applied prior to rheumatologic evaluation, a positive definition was neither sensitive (10%) nor predictive (PPV 3%). Sensitivity analyses with fulfilment of the 2010 criteria for RA or initiation of DMARDs <2-years of follow-up as external reference showed similar results.

Conclusions The EULAR definition of arthralgia suspicious for progression to RA is sensitive when used to support the expert's opinion on imminent RA. It was not discriminative in patients without prior rheumatologic evaluation. These data suggest that the definition should be used as designed and serves to further homogenize patients that rheumatologists consider at risk for RA.

References

1. van Steenbergen HW, Aletaha D, Beaart-van de Voorde LJJB de, et al. EULAR definition of arthralgia suspicious for progression to rheumatoid arthritis. Ann Rheum Dis 2016; annrheumdis-2016–209846. doi:10.1136/annrheumdis-2016–209846.

References

Disclosure of Interest None declared