Thinking Outside the Joints: The Impact of Nonarticular Pain on Patient-Reported Outcomes in a Prospective Longitudinal Real-World Early Rheumatoid Arthritis Cohort.

Abstract

We aimed to understand the association of nonarticular pain (NAP), regional and widespread, with patient-reported outcomes in early rheumatoid arthritis (RA). This real-world, multicenter study observed participants with newly diagnosed active early RA (symptoms <1 year; Clinical Disease Activity Index [CDAI] score >2.8) over the first year. Participants were examined by rheumatologists and synchronously completed body pain diagrams and Patient-Reported Outcomes Measurement Information System 29 (PROMIS-29) measures at regular intervals. Participants were classified as follows: (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. These 472 participants with early RA were mostly women (66%), had a mean age of 57 (SD 14) years, and had active disease (mean CDAI 27.0 [SD 14.1]). Over one-half (n = 246, 52%) reported NAP at baseline; of these, 72% (176 of 246) had regional NAP, and 28% (70 of 246) had widespread NAP. Adjusted mean change in PROMIS-29 domains were significantly worse in patients with regional versus no NAP: physical function -1.4 (95% confidence interval [CI] -2.1 to -0.7), pain interference 2.7 (95% CI 1.9-3.5), sleep disturbance 1.2 (95% CI 0.4-2.0), fatigue 2.1 (95% CI 1.2-3.1), anxiety 1.5 (95% CI 0.7-2.4), depression 1.4 (95% CI 0.5-2.2), and social participation -2.4 (95% CI -3.3 to -1.5). Associations between widespread and no NAP were larger for pain interference (5.0 [95% CI 3.7-6.4]), fatigue (3.2 [95% CI 1.7-4.8]), and social participation (-5.6 [95% CI -7.2 to -4.0]). Mean physical function, pain interference, and social participation scores were well outside the normal range. NAP interferes with key aspects of well-being in early RA. 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.