Characterizing Nonarticular 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: Our objective was to characterize nonarticular pain (NAP) at early rheumatoid arthritis (RA) diagnosis, the evolution over the first year of treatment, associations with active RA inflammation, and the impact on remission.

Methods: This real-world, longitudinal multicenter cohort study observed participants with active early RA (symptoms <1 year and Clinical Disease Activity Index [CDAI] >2.8) enrolled between January 2017 and January 2022 who completed a body pain diagram 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 the presence of pain in each NAP section. Multiadjusted generalized estimating equations regression models estimated associations of NAP patterns with remission outcomes.

Results: Participants (N = 392) were 70% female, with a mean ± SD age of 56 ± 14 years and mean ± SD symptoms duration of 5.1 ± 2.7 months. More than 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%). A total of 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 versus areas without NAP. Regional and widespread NAP were associated with lower odds of reaching CDAI remission (adjusted odds ratio 0.42, 95% confidence interval 0.26-0.70 and adjusted odds ratio 0.30, 95% confidence interval 0.12-0.74), 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.