Defining Bath Ankylosing Spondylitis Disease Activity Index Cut‐off Values for Disease Activity States in a Multinational European Cohort of Patients With Axial Spondyloarthritis
Year: 2025
Type: article
Study design: Observational Study
Abstract: OBJECTIVE: The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is widely used for assessing disease activity in patients with axial spondyloarthritis (axSpA), particularly in settings where markers of inflammation are unavailable. As no consensus on BASDAI cut-off values exists for disease activity states in axSpA, we aimed to develop and validate such cut-offs against external criteria. METHODS: Routine care patients with axSpA initiating a biologic disease-modifying antirheumatic drug in eight European registries were included. Receiver operating characteristic analyses against external criteria were performed to determine optimal BASDAI values for separating remission, low disease activity (LDA), high disease activity (HDA), and very high disease activity (VHDA). Follow-up data at 6 months were used to select BASDAI cut-off values between remission and LDA and between LDA and HDA, whereas baseline data were used to select the cut-off for VHDA. The level of agreement between disease activity states based on BASDAI and Axial Spondyloarthritis Disease Activity Score (ASDAS) cut-off values was assessed using the proportion of discordance and weighted kappa. RESULTS: In this cohort of 4,633 patients, the optimal BASDAI cut-off values between remission, LDA, HDA and VHDA were estimated to be <1.3, <2.5, and >5.3. The proportions of discordance between BASDAI and ASDAS disease activity states were 27.6% (weighted κ = 0.48) in baseline data and 37.6% (weighted κ = 0.28) in 6-month data. CONCLUSION: BASDAI cut-off values for separating remission, LDA, HDA and VHDA were estimated in >4,600 patients. These cut-off values can be used for assessing disease activity and monitoring patients with axSpA, particularly when laboratory markers are unavailable.
Source: ACR Open Rheumatology
DOI: 10.1002/acr2.70125
Authors: Stylianos Georgiadis, Lykke Midtbøll Ørnbjerg, Brigitte Michelsen, Tore K. Kvien, Mehrdad Shoae Kazemi, Jakub Závada, Karel Pavelka, Bente Glintborg, Anne Gitte Loft, Andreas Reich, Anne C. Regierer, Ana Maria Rodrigues, Maria José Santos, Jarno Rutanen, Laura Kuusalo, Adrian Ciurea, Michael J. Nissen, Bjorn Gudbjornsson, Ólafur Pálsson, Žiga Rotar, Katja Perdan Pirkmajer, Daniela Di Giuseppe, Mikkel Østergaard, Merete Lund Hetland
Institutions: Glostrup Hospital, Rigshospitalet, Diakonhjemmet Hospital, Sørlandet Sykehus, University of Oslo, Charles University, Institute of Rheumatology, University of Copenhagen, Aarhus University Hospital, German Rheumatism Research Centre, University of Lisbon, Hospital Garcia de Orta, Instituto de Medicina Molecular João Lobo Antunes, Centro Académico de Medicina de Lisboa, Comprehensive Health Research Centre, Tampere University Hospital, University of Turku, Turku University Hospital, University of Zurich, University Hospital Zurich, University Hospital of Geneva, University of Iceland, National University Hospital of Iceland, Lund University, Skåne University Hospital, University of Ljubljana, Ljubljana University Medical Centre, Karolinska Institutet
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,550
Funders: UCB, Union Chimique Belge, Novartis Pharma
OpenAlex ID: W4416903286