Thinking Outside the Joints: The Impact of Non-Articular Pain on Patient Reported Outcomes in a Prospective Longitudinal Real-World Early RA Cohort.

Objective: We aimed to understand the association of non-articular pain(NAP), regional and widespread, with patient-reported outcomes in early RA(eRA).

Methods: This real-world, multi-center study followed participants with newly diagnosed active eRA (symptoms<1 year, CDAI>2.8) over the first year. Participants were examined by rheumatologists and synchronously completed body pain diagrams and Patient Reported Outcomes Measurement Information System(PROMIS)29® measures at regular intervals. Participants were classified as: 1) no NAP 2) regional NAP or 3) widespread NAP. Associations between repeated measures of NAP and PROMIS-29 over the first year were estimated in separate mixed models, adjusting for sociodemographic and RA characteristics and time-varying CDAI.

Results: These 472 eRA participants were mostly women(66%), with mean(SD) age 57(14) and had active disease(mean(SD) CDAI 27.0(14.1)). Over half (n=246, 52%) reported NAP at baseline; of these, 72%(176/246) had regional and 28%(70/246) had widespread NAP. Adjusted mean- changes[95%CI] in PROMIS29 domains were significantly worse in patients with regional vs no NAP: physical function -1.4[-2.1, -0.7], pain interference 2.7[1.9, 3.5], sleep disturbance 1.2 [0.4, 2.0], fatigue 2.1[1.2, 3.1], anxiety 1.5[0.7, 2.4], depression 1.4[0.5, 2.2] and social participation -2.4[-3.3, -1.5]. Associations between widespread vs no NAP were larger for pain interference 5.0[3.7, 6.4], fatigue 3.2(1.7, 4.8) and social participation -5.6[-7.2, -4.0]. Mean physical function, pain interference and social participation scores were well outside the normal range.

Conclusion: NAP interferes with key aspects of well-being in eRA. Individuals with NAP experience greater pain interference and impairments in physical and social function, supporting a need for earlier identification of and interventions targeting NAP.