Validity of the rheumatoid arthritis impact of disease (RAID) score and definition of cut-off points for disease activity states in a population-based European cohort of patients with rheumatoid arthritis

• Published in: Joint, bone, spine : revue du rhumatisme bone, spine : revue du rhumatisme, 2018-05, Vol.85 (3), p.317-322
• Main Authors: Salaffi, Fausto, Di Carlo, Marco, Vojinovic, Jelena, Tincani, Angela, Sulli, Alberto, Soldano, Stefano, Andreoli, Laura, Dall’Ara, Francesca, Ionescu, Ruxandra, Simić Pašalić, Katarina, Balčune, Ineta, Ferraz-Amaro, Iván, Tlustochowicz, Malgorzata, Butrimienė, Irena, Punceviciene, Egle, Toroptsova, Natalia, Grazio, Simeon, Morović-Vergles, Jadranka, Masaryk, Pavol, Otsa, Kati, Bernardes, Miguel, Boyadzhieva, Vladimira, Cutolo, Maurizio
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antirheumatic Agents - therapeutic use; Area Under Curve; Arthritis, Rheumatoid - diagnosis; Arthritis, Rheumatoid - drug therapy; C-Reactive Protein - analysis; Cross-Sectional Studies; Databases, Factual; Disease activity; Europe; Female; Humans; Male; Middle Aged; Patient Reported Outcome Measures; Patient-reported outcomes; Prognosis; RAID; Rheumatoid arthritis; Rheumatologists - statistics & numerical data; ROC Curve; Severity of Illness Index; Sickness Impact Profile
• ISSN: 1297-319X; 1778-7254
• DOI: 10.1016/j.jbspin.2017.05.020

To assess the validity of the rheumatoid arthritis impact of disease (RAID) for measuring disease activity of rheumatoid arthritis (RA) and to determine cut-off values for defining the disease activity states. A total of 622 RA patients from an European database have been included. Cross-validation was based on assessment of convergent and discriminant validity. Optimal cut-offs were determined against external criteria by calculating the respective 25th and 75th percentiles mean values of RAID. External criteria included definitions for remission (REM), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA), cut-offs of the 28-joint disease activity score-C-reactive protein (DAS28-CRP) score. The RAID showed a moderate degree of correlation with respect to DAS28-CRP (rho=0.417; P4 and ≤6; for HDA: RAID >6. Mean RAID differed significantly between patients classified as REM, LDA, MDA or HDA (P=0.001). The cut-offs revealed good measurement characteristics in cross-validation analysis, had great discriminatory performance in distinguishing patients with different levels of disease activity and are suited for widespread use in everyday practice application and research.