Patients with early rheumatoid arthritis (RA) may present with more tender than swollen joints, which can persist. An elevated tender-swollen joint difference (TSJD) may have multiple causes and it may contribute to overestimates of disease activity. Little is known about the phenotype and impact of this difference on patient function. In a new study published in ACR Open Rheumatology, Meng et al. evaluated the impact of TSJD on functional outcomes in early RA and whether associations vary by joint size.
Methods
Data were obtained from patients with active, early RA (≤12 months) enrolled in the Canadian Early Arthritis Cohort who completed assessments of general function (Multidimensional Health Assessment Questionnaire [MDHAQ]), upper extremity (UE) function (Quality of Life in Neurological Disorders [Neuro-QoL] UE scale), and work/activity impairment (Work Productivity and Activity Impairment RA) over their first year of follow-up. In total, 28 joint counts were performed. TSJDs were calculated. Adjusted associations between TSJDs and functional outcomes were estimated in separate multi-variable linear mixed effects models. Separate analyses were performed for large- vs. small-joint TSJD.
Results
Of 547 patients, most were women (70%) with a mean age of 56 years (standard deviation [SD]: 15) and a mean disease duration of 5.3 months (SD 2.9). At baseline, 287 (52%) had TSJD >0 (43% involved large joints and 34% small joints), decreasing to 32% at 12 months. A one-point increase in TSJD was significantly associated with worse function (MDHAQ: adjusted mean change 0.10, 95% confidence interval [CI] 0.08–0.13; Neuro-QoL UE function T score: adjusted mean change −0.59, 95% CI −0.76 to −0.43; and greater work impairment: adjusted mean change 1.95%, 95% CI 0.85%–3.05%). Higher large-joint TSJDs were associated with the worst functional outcomes.
Conclusion
Having more tender than swollen joints is common in early RA and is associated with worse function, most notably when involving large joints. Early identification and targeted intervention strategies may be needed.
For complete details, including source material, refer to the full study.
Excerpted & Adapted From
Meng CF, Lee Y, Schieir O, et al. Having more tender than swollen joints is associated with worse function and work impairment in patients with early rheumatoid arthritis. ACR Open Rheumatol. 2024 Jun;6(6):347–355.