Chronic Widespread Pain in Patients with Rheumatoid Arthritis and the Relation Between Pain and Disease Activity Measures over the First 5 Years

Abstract

To study the prevalence of chronic widespread pain (ChWP), chronic regional pain (ChRP), and fibromyalgia in patients with early rheumatoid arthritis (RA) followed for 5 years after inclusion, and to study the effect of pain on measures of disease activity and function. A questionnaire was sent to 1910 patients participating in the Better Anti-Rheumatic Pharmacotherapy study. The responders (73%) were divided into 3 groups according to the reported pain duration and distribution - patients having no chronic pain (NChP), ChWP, and ChRP. Outcome measures were the 28-joint Disease Activity Score (DAS28), the Health Assessment Questionnaire (HAQ), and C-reactive protein (CRP). Thirty-four percent of respondents reported ChWP, 46% ChRP, and 20% NChP. Patients reporting ChWP were more often women and had more pain and tender joints at inclusion. From 6 months to 5 years of followup, mean DAS28, visual analog scale (VAS) pain, VAS global health, and HAQ were significantly higher in the ChWP group than in the other groups. However, all groups showed a similar pattern in swollen joint count, erythrocyte sedimentation rate (ESR), and CRP. From 12 months the ChWP group was treated with prednisolone to a greater extent than the ChRP group, and it had a rate of treatment with disease-modifying antirheumatic drugs similar to that of the ChRP group. ChWP is a common feature in RA, more associated with high values for variables related to pain such as the DAS28 and HAQ than to indicators of ongoing inflammation such as swollen joint count, ESR, and CRP. Patients with ChWP should be identified so that adequate treatment also of the noninflammatory pain may be instituted.