Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Mar 15;57(2):256-60.
doi: 10.1002/art.22531.

The Disease Activity Score in 28 joints in rheumatoid arthritis and psoriatic arthritis patients

Burkhard F Leeb  1 , Ingrid Andel, Judith Sautner, Christian Fassl, Thomas Nothnagl, Bernhard Rintelen
Affiliations

The Disease Activity Score in 28 joints in rheumatoid arthritis and psoriatic arthritis patients

Burkhard F Leeb et al. Arthritis Rheum. .

Abstract

Objective: To assess the factorial structure of the Disease Activity Score including a 28-joint count (DAS28) if applied in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

Methods: DAS28 values from 85 consecutive PsA outpatients and 2 RA patient cohorts comprising 85 patients each were compared. The first RA cohort (RA1) consisted of age- and sex-matched patients seen during the same period as the patients with PsA. The first 85 RA outpatients from September 2003 were included in the second cohort (RA2). Item weighting, factor loading, and internal consistency were assessed by factor analysis, principal component analysis, and calculation of Cronbach's alpha.

Results: The mean +/- SD DAS28 scores of patients in the PsA, RA1, and RA2 cohorts were 3.2 +/- 1.31, 3.21 +/- 1.45, and 3.79 +/- 1.44, respectively. A significant difference between the PsA and RA2 cohorts was found for DAS28 (P = 0.0063), swollen joint count (P = 0.007), and patient's global assessment (P < 0.001), but not for erythrocyte sedimentation rate. Internal consistency of the DAS28 in patients with PsA was considerably lower, item weighting showed remarkable differences, and factor analysis revealed that the DAS28 constitutes a bidimensional instrument in patients with PsA, whereas in both RA cohorts it appeared to be monodimensional.

Conclusion: With respect to its statistical properties, the DAS28 proved to be considerably different in PsA compared with RA. Therefore its application for disease activity assessment in patients with PsA cannot be recommended without a formal validation procedure.

PubMed Disclaimer