High rates of fibromyalgia (FM) are reported in rheumatoid arthritis (RA) patients. Advances in RA management have occurred, but information regarding current significance of FM in RA is limited. This investigation estimated the prevalence and health effects of concomitant FM in Australian RA patients.
Participants were recruited from Australian rheumatology clinics. Subjects were assessed using the 1990 and 2011 American College of Rheumatology (ACR) FM criteria and the polysymptomatic distress score (PDS) was calculated. A medical history and a clinical examination were recorded. RA Disease Activity Score of 28 joints - erythrocyte sedimentation rate (DAS-28 ESR), and the Short Form-36 survey (SF-36) were completed.
Of 117 RA patients, 33.3% (n = 39) met 1990 ACR FM criteria and 41.9% (n = 49) met 2011 ACR FM criteria. RA patients with comorbid FM had worse outcomes across all domains of health as defined by the SF-36 (P < 0.05). There was correlation between both physical and mental health outcomes and the PDS (P < 0.001). RA patients with FM on average took 1.18 extra ongoing prescribed medications (P < 0.05), despite comparable RA disease activity (DAS-28: 3.09 vs. 3.27, P = NS). Comorbid central sensitivity conditions were more common in patients with FM (P < 0.001).
FM continues to demonstrate a high prevalence in a population of RA patients. RA patients with FM have more symptoms of other chronic sensitivity syndromes in addition to FM. They have a lower quality of life outcome and higher medication use. This has important clinical implications in terms of diagnosis, response to therapy, prescribing choices and clinical outcomes.