The DAS28 in rheumatoid arthritis and fibromyalgia patients

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Rheumatology (Oxford). 2004 Jul 13

The DAS28 in rheumatoid arthritis and fibromyalgia patients.

Leeb BF, Andel I, Sautner J, Nothnagl T, Rintelen B.

HUMANIS Klinikum Lower Austria, Lower Austrian Center for Rheumatology,

Stockerau, Austria.

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<0.0005) occurred

between RA and FM patients. Cronbach's alpha for the DAS28 in RA patients

amounted to 0.7329, indicating high internal consistency, whereas in FM

patients it was 0.4832. CONCLUSION: The DAS28, as expected, proved to be

inappropriate to express disease activity in FM patients. DAS28 values for

expressing disease activity in RA patients may be flawed by coexisting FM

and should therefore be regarded with caution as high pain levels more than

impaired mood may lead to higher total scores.

PMID: 15252215 [PubMed - as supplied by publisher]