Risk factors of nociplastic pain in patients with autoimmune arthritis: web-based cross-sectional survey of patients.

This study aimed to identify risk factors of nociplastic pain in patients with autoimmune arthritis. Patients suffering from chronic pain and autoimmune arthritis were invited to participate in a study via moderated support groups on social media. Each invitation included a brief description of nociplastic pain. The study cohort comprised 185 patients, primarily those with rheumatoid arthritis (64%) and spondyloarthropathies (27%). 82% of patients scored positively (≥ 40 points) on the Central Sensitization Inventory (CSI), while 57% showed a neuropathic component as indicated by the PainDetect Questionnaire (PDQ). Of the participants with a positive CSI score, 86% achieved at least a borderline grade on the PDQ. More frequent use of painkillers (> once a day) correlated with higher CSI scores (mean difference (MD) = 7.1, p = 0.039, and MD = 8, p = 0.005 compared to daily and less frequent use, respectively). In a multivariable linear regression model, factors such as depression (β = 8.7, p < 0.001), nocturnal pain (β = 4.5, p = 0.013), need for painkillers (β = 5.3, p = 0.032), disease duration > 2 years (β = 3.3, p = 0.036), Chronic Pain Grade Scale (β = 2.8, from I to IV grade, p < 0.001), and worse mood (β = -0.9, on a 0-10 scale, p = 0.031) were independently associated with higher CSI scores. Nocturnal pain and pain-related disability may serve as clinical risk factors of nociplastic pain. The PDQ may lose its reliability in detecting neuropathic pain in patients with a high nociplastic component.