918 The Journal of Rheumatology 2009; 36:5; doi:10.3899/jrheum.080863 Personal non-commercial use only. The Journal of Rheumatology Copyright © 2009. All rights reserved. The Rheumatoid Arthritis Disease Activity Index-5 in Daily Use. Proposal for Disease Activity Categories BERNHARD RINTELEN, PIA M. HAINDL, JUDITH SAUTNER, BARBARAA. LEEB, CHRISTOPH DEUTSCH, and BURKHARD F. LEEB ABSTRACT. Objective. To establish thresholds for rheumatoid arthritis (RA) activity categories according to the RA DiseaseActivity Index-5 (RADAI-5). Methods. Three hundred ninety-two patients with RA were categorized according to Disease Activity Score 28-joint count (DAS28), Clinical DiseaseActivity Index (CDAI), and their satisfac- tion(PATSAT)withdiseasestatus.Thesemeasuresbuiltthebasisforthecalculationofdiseaseactiv- itylimitsfortheRADAI-5.PatientassessmentssimultaneouslymeetingtheidenticalDAS28,CDAI, and PATSAT categories were taken as the references to establish the thresholds for the respective RADAI-5 categories by calculating the third quartile of the corresponding RADAI-5 values. Subsequently, these new thresholds were applied to all assessments. Results. Seven hundred fifty-eight assessments in 392 patients (2 assessments median/patient) could be obtained, most patients having mild to moderate disease according to DAS28 and CDAI. Calculating the third quartile, the RADAI-5 thresholds were as follows: 0.0–1.4 for a remission-like state, 1.6–3.0 for mild disease activity, 3.2–5.4 for moderate, and 5.6–10.0 for high disease activity. Categorization according to the RADAI-5 showed a normal distribution, while DAS28 and CDAI were somewhat shifted to the left. DAS28 and CDAI levels, as well as tender and swollen joint counts and physician’s global assessment and erythrocyte sedimentation rate, proved to be highly significantly different within the different RADAI-5 categories (Kruskal-Wallis test p < 0.001). Conclusion. RADAI-5 thresholds for RA activity could be elaborated. Patient self-report question- naires may substitute composite disease activity scores and may contribute significantly to improv- ingdocumentationinroutinepatientcare.(FirstReleaseApril12009;JRheumatol2009;36:918–24; doi:10.3899/jrheum.080863) Key Indexing Terms: RHEUMATOIDARTHRITIS RHEUMATOIDARTHRITIS DISEASEACTIVITY INDEX-5 DISEASEACTIVITYASSESSMENT DAILYROUTINE From the 1st and 2nd Department of Medicine, Center for Rheumatology, Lower Austrian State Hospital, Stockerau; and the Private Rheumatology Office of Dr. B.F. Leeb, Hollabrunn, Austria. B. Rintelen, MD; P.M. Haindl, MD; J. Sautner, MD, 1st and 2nd Department of Medicine, Center for Rheumatology, Lower Austrian State Hospital Stockerau; B.A. Leeb, private practice; C. Deutsch, MD, 1st and 2nd Department of Medicine, Center for Rheumatology, Lower Austrian State Hospital Stockerau; B.F. Leeb, MD, private practice, Director, 1st and 2nd Department of Medicine, Center for Rheumatology, Lower Austrian State Hospital Stockerau. Address reprint requests to Dr. B.F. Leeb,Waldweg 32, A-2020 Hollabrunn, Austria. E-mail: burkhard.leeb@stockerau.lknoe.at Accepted for publication December 16, 2008. Valid measurement tools are a necessity for disease activity assessment in patients with rheumatoid arthritis (RA) in daily routine care. Important prerequisites of valid instru- mentsaretheirfeasibilityaswellaseasyapplicability.Itcan be anticipated that assessment of patients applying valid tools, regardless of composite indexes or patient question- naires, would result in better patient outcome. Nevertheless, most physicians unfortunately do not use disease activity assessment tools in daily practice 1 . Almost all composite disease activity scores, like the Disease Activity Score (DAS28) 2 or the Clinical Disease Activity Index (CDAI) 3 use a 28-joint count requiring experience in joint assessment. We recently published a 5-item questionnaire — the RADAI-5 4 , a modification of the Rheumatoid Arthritis Disease Activity Index — for patient-centered RA activity assessment. The RADAI-5 omits the patient self-assessed tender joint count (TJC) of the original RADAI 5 . The background for doing so was to provide physicians, particularly the non-rheumatologist, who may not be that familiar with joint assessment, with an instrument to assess RA activity in daily routine care. The RADAI-5, a completely patient self-administered tool, was shown to be capable of measuring RA activity accurately when compared to the DAS28 and the CDAI. Moreover, its reliability and convergent validity could be documented 4 . To date, thresholds for disease activity categories have not yet been defined for this instrument. Therefore, this investigation was performed to establish cutoff values for theRADAI-5definingaremission-likestateaswellasmild, moderate, and high disease activity. Such thresholds have been evaluated for the composite indexes as well as for another patient self-report questionnaire, namely the www.jrheum.org Downloaded on July 24, 2021 from