Characterizing Non-Articular Pain at Early Rheumatoid Arthritis Diagnosis, Evolution over the First year of Treatment and Impact on Remission in a Prospective Real-World Early Rheumatoid Arthritis Cohort.

Abstract

Objective: To characterize non-articular pain (NAP) at early RA diagnosis, the evolution over the first year of treatment, associations with active RA inflammation and impact on remission.

Methods: This real-world, longitudinal multi-center cohort study followed participants with active early RA (symptoms<1 year, CDAI>2.8,) enrolled between 1/2017 and 1/2022, and who completed a body pain diagram (BPD) over 1-year. Participants were grouped by prespecified definitions of NAP: 1) none 2) regional or 3) widespread. Rheumatologists performed joint counts. Descriptive statistics summarized the frequency and evolution of NAP patterns over 1-year. Chi-square tests compared the proportions of tender and/or swollen joints by presence of pain in each NAP section. Multi-adjusted GEE regression models estimated associations of NAP patterns with remission outcomes.

Results: Participants (N=392) were 70% female, mean(Sd) age of 56(14) years and mean symptoms duration of 5.1(2.7) months. Over half reported NAP at baseline with most (73%) presenting with regional NAP. Common patterns of regional NAP were axial (40%) and pain in upper quadrants (17%). 43% of those with regional NAP persisted or worsened over 1-year, whereas 73% of those with widespread NAP resolved or improved. Joint inflammation was more frequently reported in areas with NAP vs areas without NAP. Regional and widespread NAP were associated with lower odds of reaching CDAI remission (adjusted OR [95%CI]):0.42[0.26 to 0.70] and 0.30[0.12 to 0.74], respectively.

Conclusion: Regional NAP is common and persistent in early RA and impacts remission. RA activity may contribute to NAP. More attention to NAP in RA care is warranted.