Value of RAPID3 in patients with PsA: results from the TICOPA and LOPAS II databases.
Coates LC., Tillett W., Shaddick G., Pincus T., Kavanaugh A., Helliwell PS.
OBJECTIVE: To analyze RAPID3, a patient-reported, composite index, designed initially for feasibility in clinical care. RAPID3 was developed in rheumatoid arthritis, but has been found useful in many rheumatic diseases. We analysed RAPID3 in patients with psoriatic arthritis (PsA). METHODS: Post-hoc analyses were performed on two independent datasets, the tight control of PsA (TICOPA) clinical trial, and the long-term outcome in PsA study (LOPAS II), an observational cohort. RAPID3 (0-30) is the total of three 0-10 scores for HAQ-DI (recalculated from 0-3), pain visual analog scale (VAS), and global VAS. RAPID3 scores were compared to the PsA disease activity score (PASDAS) and disease activity in psoriatic arthritis (DAPSA) and other available clinical measures, according to Spearman correlation coefficients, standardised response mean (SRM), standard error of the mean (SEM), smallest detectible difference (SDD), minimally important difference (MID in patients who improved) and receiver-operating characteristic (ROC) curves. RAPID3 remission was compared to criteria for both standard minimal disease activity (MDA) and very low disease activity (VLDA). RESULTS: RAPID3 was correlated significantly with PASDAS in TICOPA (r=0.79, p<0.01) and with DAPSA in LOPAS (rho=0.59, p<0.01), and with most other measures in both datasets. RAPID3 discriminated between tight control and standard care in TICOPA at 48 weeks at levels comparable to DAPSA and the PASDAS (p<0.01). RAPID3 remission discriminated treatment groups in TICOPA intermediate between MDA and VLDA criteria. CONCLUSION: RAPID3 appears comparably informative to PASDAS and DAPSA in PsA, with greater feasibility for routine clinical care. This article is protected by copyright. All rights reserved.