RAPID3 (Routine Assessment of Patient Index Data 3), a rheumatoid arthritis index without formal joint counts for routine care: Proposed severity categories compared to disease activity score and clinical disease activity index categories

Abstract

Objective. To compare 4 categories (high, moderate, and low severity, and near-remission) of RAPID3 (Routine Assessment of Patient Index Data 3), an index without formal joint counts, which is scored in < 10 seconds to 4 categories of the Disease Activity Score (DAS28) and Clinical Disease Activity Index (CDAI) in patients with rheumatoid arthritis (RA). Methods. All patients complete a Multidimensional Health Assessment Questionnaire (MDHAQ) at each visit. A physician/assessor 28-joint count and erythrocyte sedimentation rate (ESR) were completed in 285 patients with RA in usual care by 3 rheumatologists to score DAS28, CDAI, and RAPID3. RAPID3 includes the 3 MDHAQ patient self-report RA Core Data Set measures for physical function, pain, and patient global estimate. Proposed RAPID3 (range 0-10) severity categories of high (> 4), moderate (2.01-4), low (1.01-2), and near-remission (≤ 1) were compared to DAS (0-10) activity categories of high (> 5.1), moderate (3.21-5.1), low (2.61-3.2), and remission (≤ 2.6), and CDAI (0-76) categories of > 22, 10.1-22.0, 2.9-10.0, and ≤ 2.8. Additional RAPID scores, which add to RAPID3 a physician/assessor or patient self-report joint count and/or assessor global estimate, were also analyzed. Statistical significance was analyzed using Spearman correlations, cross-tabulations, and kappa statistics. Results. All RAPID scores were correlated significantly with DAS28 and CDAI (rho > 0.65, p < 0.001). Overall, 78%-84% of patients who met DAS28 or CDAI moderate/high activity criteria met similar RAPID severity criteria, and 68%-77% who met DAS28 or CDAI remission/low activity criteria also met similar RAPID criteria. RAPID3 was as informative as other indices. Conclusion. RAPID3 provides a feasible, informative quantitative index for busy clinical settings.