1 Garrido-Castro, et al: Reproducibility of UCOASMI Personal non-commercial use only. The Journal of Rheumatology Copyright © 2018. All rights reserved. High Reproducibility of an Automated Measurement of Mobility for Patients with Axial Spondyloarthritis Juan L. Garrido-Castro, Rafael Curbelo, Ramón Mazzucchelli, María E. Domínguez-González, Cristina Gonzalez-Navas, Bryan J. Flores Robles, Pedro Zarco, Juan Mulero, Luis Cea-Calvo, María J. Arteaga, Pilar Font-Ugalde, Loreto Carmona, and Eduardo Collantes-Estevez ABSTRACT. Objective. Conventional measures of spinal mobility used in the assessment of patients with axial spondyloarthritis (axSpA), such as the Bath Ankylosing Spondylitis Metrology Index and its compo- nents, are subject to interobserver variability. The University of Córdoba Ankylosing Spondylitis Metrology Index (UCOASMI) is a validated composite index based on a motion video-capture system, UCOTrack. Our objective was to assess its reproducibility in clinical practice settings. Methods. We carried out an observational study of repeated measures in 3 centers. Video-capture systems were installed and adapted to clinical rooms. Patients with axSpA and stable disease were selected by consecutive stratified sampling [disease duration, sex, and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)]. Intraobserver reliability of the UCOASMI and of conventional measures was tested 3–5 days apart. For interobserver reliability, 3 patients from each center were evaluated in the other centers, within 3–7 days. The intraclass correlation coefficients (ICC) were calculated. Results. Thirty patients were included (73% men, mean age 53 yrs, mean BASDAI 3.0). Interobserver and intraobserver ICC of the UCOASMI was 0.98. Conventional measurements showed lower but adequate reproducibility as well, except for interobserver reliability of lateral flexion (0.41), cervical rotation (0.61), and Schöber test (0.07), and intraobserver reliability of tragus-to-wall distance (0.30). Conclusion. Reproducibility of the UCOASMI seems very high, and apparently more reliable than conventional measures of mobility. (J Rheumatol First Release June 15 2018; doi:10.3899/ jrheum.170941) Key Indexing Terms: SPONDYLOARTHROPATHY OUTCOME ASSESSMENT SPINE From the Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC); Department of Rheumatology, Hospital Universitario Reina Sofía; Department of Medicine, Universidad de Córdoba, Córdoba; Instituto de Salud Musculoesquelética; Department of Rheumatology, Hospital Fundación Alcorcón, Alcorcón; Department of Rheumatology, Hospital Puerta de Hierro, Majadahonda; Medical Affairs, Merck Sharp & Dohme, Madrid, Spain. Study funded by Merck Sharp & Dohme of Spain. Dr. L. Cea-Calvo and Dr. M.J. Arteaga are full-time employees at Merck Sharp & Dohme of Spain. UCOTrack is owned by the University of Córdoba and the Andalusian Health Service. J.L. Garrido-Castro, IE, PhD, IMIBIC; R. Curbelo, PT, PhD, Instituto de Salud Musculoesquelética; R. Mazzucchelli, MD, Department of Rheumatology, Hospital Fundación Alcorcón; M.E. Domínguez-González, RN, Department of Rheumatology, Hospital Fundación Alcorcón; C. Gonzalez-Navas, RN, IMIBIC, and Department of Rheumatology, Hospital Universitario Reina Sofía; B.J. Flores Robles, MD, Department of Rheumatology, Hospital Puerta de Hierro; P. Zarco, MD, PhD, Department of Rheumatology, Hospital Fundación Alcorcón; J. Mulero, MD, PhD, Department of Rheumatology, Hospital Puerta de Hierro; L. Cea-Calvo, MD, Medical Affairs, Merck Sharp & Dohme; M.J. Arteaga, MD, Medical Affairs, Merck Sharp & Dohme; P. Font-Ugalde, MD, PhD, IMIBIC, and Department of Rheumatology, Hospital Universitario Reina Sofía, and Department of Medicine, Universidad de Córdoba; L. Carmona, MD, PhD, Instituto de Salud Musculoesquelética; E. Collantes-Estevez, MD, PhD, IMIBIC, and Department of Rheumatology, Hospital Universitario Reina Sofía, and Department of Medicine, Universidad de Córdoba. Address correspondence to Dr. J.L. Garrido-Castro, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain. E-mail: cc0juanl@uco.es Accepted for publication February 28, 2018. Axial spondyloarthritis (axSpA) is characterized by structural damage 1 , dependent on the inflammatory process, and manifested as bone erosions, resorption, and new bone formation 2,3 . The result is a significant reduction of joint mobility and pain, which in turn lead to disability and deteri- oration of quality of life 4,5,6 . The objective of therapy in axSpA is 2-fold: halting the inflammatory process at present, and avoiding structural damage and disability in the future while improving patients’ quality of life. The field of measurement in axSpA has evolved in parallel to the devel- opment of new drugs, and measures of disease activity and structural damage are reasonably well accepted for use in clinical trials and in clinical practice. The measurement of damaged mobility, on the contrary, has problems. Spinal mobility can be assessed by 2 types of instruments: (1) standardized measures of range of motion and distance, in www.jrheum.org Downloaded on December 3, 2021 from