J Rheum Dis  
Implications of Persistent Pain in Patients With Rheumatoid Arthritis Despite Remission Status: Data From the KOBIO Registry
Hyoun-Ah Kim, M.D., Ph.D.1, So Young Park, M.S.2, Kichul Shin, M.D., Ph.D.2
1Department of Rheumatology, Ajou University School of Medicine, Suwon, 2Divison of Rheumatology, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea
Correspondence to: Kichul Shin, http://orcid.org/0000-0002-6749-7598
Division of Rheumatology, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, 20 Boramae-ro 5-gil, Dongjak-gu, Seoul 07061, Korea. E-mail: kideb1@snu.ac.kr
Received: February 6, 2022; Revised: June 7, 2022; Accepted: June 10, 2022; Published online: June 30, 2022.
© Korean College of Rheumatology.

This is a open Access article, which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objective: This study aimed to assess the prevalence of pain in patients with RA in clinical remission and analyze the demographic and clinical characteristics of those who experienced persistent pain despite remission status.
Methods: Data from 1,891 patients with RA registered on the Korean College of Rheumatology Biologics and Targeted Therapy registry were obtained. Remission was defined as a Disease Activity Score of 28 joints-erythrocyte sedimentation rate (ESR) <2.6. Pain intensity was classified as severe (pain visual analog scale [VAS] ≥7), moderate (4≤VAS<7), or mild (VAS <4).
Results: Our analysis showed that 52.6% of patients complained of severe pain at the start of or during switching biological disease- modifying anti-rheumatic drugs (bDMARDs) or targeted synthetic DMARDs (tsDMARDs). Despite having a 36.0% (n=680) remission rate after the use of bDMARDs or tsDMARDs at their 1-year follow-up, 21.5% (n=146) of these patients had moderateto- severe pain, higher frequency of foot erosions, and comorbidities, such as mental illness, endocrine, renal, and neurological disorders, than patients with a milder degree of pain. The multivariable regression analysis showed that presence of foot erosions, neurological disorders, and use of corticosteroids were independently associated with moderate-to-severe pain in patients with RA despite being in remission. The level of ESR and use of Janus kinase inhibitors were inversely associated with moderate-to-severe pain.
Conclusion: Persistent pain and discomfort continue to be a problem for patients with RA in clinical remission. Continued research on insistent pain in patients with RA is warranted to better alleviate distress and improve the quality of life in patients.
Keywords: Biologics, Disease modifying antirheumatic drugs, JAK inhibitors, Pain, Rheumatoid arthritis

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