Objective. To determine which activity indices better correlate with assess
or's (AGA) and patient's (PGA) global assessment of disease activity and to
compare the improvement with American College of Rheumatology (ACR) and Eu
ropean League Against Rheumatism (EULAR) criteria and their association wit
h PGA and AGA of overall improvement.
Methods. Seventy-five patients with rheumatoid arthritis (RA) were studied.
Swollen and tender joints, morning stiffness, grip strength, pain, AGA, PG
A, Health Assessment Questionnaire (HAQ) score, erythrocyte sedimentation r
are (ESR), C-reactive protein (CPR), and hemoglobin were determined before
and 6 months after treatment. Several activity indices were calculated: Dis
ease Activity Score (DAS), DAS 3, DAS 28, DAS '28,' ACR greater than or equ
al to 20%, Mallya, Riel, IDA, and a modification of the Stoke index.
Results. All indices correlated with PGA and AGA before and after treatment
(r > 0.38, p < 0.01), but better results were obtained with AGA than PGA.
DAS, DAS 3, DAS 28, and modified Stoke had the best correlation with AGA (r
<greater than or equal to> 0.77, p < 0.01). The indices that better detect
ed the differences after treatment for AGA were DAS, DAS 3, DAS 28, and mod
ified Stoke (r <greater than or equal to> -0.42, p < 0.01). The level of ag
reement between EULAR and ACR improvement classifications with both reduced
and extensive joint counts was comparable and its association with PCA and
AGA overall improvement was significant (p < 0.01).
Conclusion. All activity indices correlated with PGA and AGA, although the
best results were: obtained with AGA. Although indices' correlations were s
imilar, the DAS group and the modified Stoke seemed to be the most useful i
ndices to measure disease activity in RA. The discriminating potential betw
een ACR and EULAR improvement classification was comparable, as was the ass
ociation with PGA and AGA overall improvement.