The DAS28 in rheumatoid arthritis and fibromyalgia patients

Objective. To compare the DAS28 (Disease Activity Score including a 28-joint count) values of rheumatoid arthritis (RA) and fibromyalgia (FM) patients, and to establish whether high pain levels and impaired mood influence DAS28 values. Methods. DAS28 values were calculated in 62 consecutive patients with RA and in 26 patients suffering from FM. Values for DAS28 scores as well as for the single items of the patient cohorts were compared using Student's t-tests. To evaluate the item weighting and internal consistency of the total score factor analysis was performed and Cronbach's alpha calculated. Results. RA patients showed a mean DAS28 score of 4.23 (±1.2; range 0.77–7.46) and in FM patients the mean DAS28 came to 4.04 (±1.13; range 1.19–6.28). DAS28 values of RA and FM patients were not significantly different statistically. Comparing the single components of the score, however, highly significant differences (P