Comparison of the Disease Activity Score and Juvenile Arthritis Disease Activity Score in the juvenile idiopathic arthritis

Introduction

The assessment of the activity of rheumatoid arthritis and juvenile idiopathic arthritis is made by means of the tools DAS-28 and JADAS, respectively.

Objective

To compare DAS-28 and JADAS with scores of 71, 27 and 10 joint counts in juvenile idiopathic arthritis.

Method

A secondary analysis of a phase III placebo-controlled trial, testing safety and efficacy of abatacept was conducted in 8 patients with 178 assessment visits. Joint count scores for active and limited joints, physician's and parents’ global assessment by 0–10 cm Visual Analog Scale, and erythrocyte sedimentation rate normalized to 0–10 scale, in all visits. The comparison among the activity indices in different observations was made through Anova or adjusted gamma model. The paired observations between DAS-28 and JADAS 71, 27 and 10, respectively, were analyzed by linear regression.

Results

There were significant differences among individual measures, except for ESR, in the first 4 months of biological treatment, when five of the eight patients reached ACR-Pedi 30, with improvement. The indices of DAS-28, JADAS 71, 27 and 10 also showed significant difference during follow-up. Linear regression adjusted model between DAS-28 and JADAS resulted in mathematical formulas for conversion: [DAS-28 = 0.0709 (JADAS 71) + 1.267] (R² = 0.49); [DAS-28 = 0.084 (JADAS 27) + 1.7404] (R² = 0.47) and [DAS-28 = 0.1129 (JADAS-10) + 1.5748] (R² = 0.50).

Conclusion

The conversion of scores of DAS-28 and JADAS 71, 27 and 10 for this mathematical model would allow equivalent application of both in adolescents with arthritis.

Juvenile idiopathic arthritis; Rheumatoid arthritis; Disease Activity Score-28; Juvenile Arthritis Disease Activity Score