| Affiliation: | 1. Rheumatology department, polytechnic university of Marche, “Carlo Urbani” hospital, via Aldo Moro 25, 60035 Jesi Ancona, Italy;2. Department pediatric rheumatology, clinical center, medical faculty, university of Nis, Bul Zoran Djindjic 81, 18000 Nis, Serbia;3. Division of rheumatology, department of clinical and experimental science, university of Brescia, ASST, Spedali Civili di Brescia, piazzale Spedali Civili 1, 25123 Brescia, Italy;4. Research laboratory and division of clinical rheumatology, department of internal medicine, university of Genova, IRCCS San Martino, Largo R. Benzi 10, 16132 Genova, Italy;5. Department of internal medicine and rheumatology, Sf. Maria Hospital, university of medicine and pharmacy “Carol Davila”, boulevard Ion-Mihalache 37-39, sector 1, 020021 Bucharest, Romania;6. Institute of rheumatology, Resavska 69, 11000 Belgrade, Serbia;g. Division of rheumatology, Paula-Stradina clinical hospital, Pilso?u 13, Nr. 26, corpuss 10, LV-1001, Riga, Latvia;h. Servicio de reumatología, hospital universitario de Canarias, Planta 5, Ofra s/n La Cuesta, 38320 Santa Cruz de Tenerife, Spain;i. Military institute of medicine, department of internal medicine and rheumatology, Szaserów 128, 04-141, Warsaw, Poland;j. Vilnius university, rheumatology center Santariskiu 2, 08406 Vilnius, Lithuania;k. RSI Center of inovative medicine, Santariskiu 5, 08410 Vilnius, Lithuania;l. Scientific research institute of rheumatology “V. A. Nasonova”, Karshirskoe shosse 34A, 115522 Moscow, Russia;m. Department of rheumatology, Sisters of Mercy clinical hospital center university, physical and rehabilitation medicine, Vinogradska 29, 10000 Zagreb, Croatia;n. Department for clinical immunology and rheumatology, clinical hospital Dubrava, school of medicine, university of Zagreb, Avenija Gojka ?u?ka 6, 10000 Zagreb, Croatia;o. National institute of rheumatic diseases, Nabrezie Ivana Krasku 4, SK-921 01 Piestany, Slovakia;p. Department of rheumatology, East Tallinn central hospital, Ravi street 18, 10138 Tallinn, Estonia;q. Rheumatology department of São João hospital center and faculty of medicine of university of Porto (FMUP), Alameda Professor Hernani Monteiro, 42000 Porto, Portugal;r. Medical university-Sofia, UMHAT “St. Iv. Rilski”, department of rheumatology, Urvich St. 13, 1612 Sofia, Bulgaria |
| Abstract: | ![]()
ObjectivesTo 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.MethodsA 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.ResultsThe RAID showed a moderate degree of correlation with respect to DAS28-CRP (rho = 0.417; P < 0.0001). The receiver operating characteristic (ROC) curves to discriminate the ability of RAID to distinguish patients with active and non-active disease was very good with an area under the curve (AUC) of 0.847 (95% confidence interval [CI]: 0.816 to 0.878; P < 0.0001). Based on the distributions of RAID in the different disease activity groups, we propose the following cut-off values for REM: RAID ≤3; for LDA: RAID >3 and ≤4; for MDA: RAID >4 and ≤6; for HDA: RAID >6. Mean RAID differed significantly between patients classified as REM, LDA, MDA or HDA (P = 0.001).ConclusionsThe 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. |
