The impact of fibromyalgia on disease assessment in rheumatoid arthritis patients

Aim of work: To explore the influence of the presence of concomitant fibromyalgia (FM) on the evaluation of disease activity score assessing 28 joints (DAS28), clinical disease activity index (CDAI) and modified health assessment questionnaire (MHAQ) in Egyptian patients with rheumatoid arthritis (RA).Patients and methods: This study included 50 female RA patients; out of which 25 had concomitant FM (RAF group), the other 25 RA patients who served as controls did not have concomitant FM (RA group). All patients were subjected to an assessment of disease activity using the DAS 28 and the CDAI and assessment of functional outcome using MHAQ score.Results: The mean DAS 28 was significantly higher in RAF than RA patients (5.6 +/- 1.1 versus 4.5 +/- 1.3, P = 0.009). Also, the mean CDAI score was significantly higher in the RAF group (mean 23.3 +/- 12.1 versus 13.7 +/- 11.0, P = 0.002). The difference was attributed to significantly higher subjective items such as Tender joint count (TJC) and patient's global assessment of general health (VAS-GH) in the RAF group. Mean MHAQ score was also higher in the RAF group (0.7 +/- 0.6 versus 0.31 +/- 0.4, P = 0.006).Conclusion: FM is related to worse scores on the DAS28, CDAI and MHAQ in patients with RA. The presence of FM may have major implications in the interpretation of the DAS28 and CDAI scores because it is related to higher scores independently of objective evidence of RA activity. (C) 2013 Production and hosting by Elsevier B.V.