SAT0719-HPR Performance-based physical function measure was more sensitive to detect responders than self-reported measure after a physical therapy exercise intervention in patients with axial spondyloarthritis

Background Physical function is regarded as an important outcome in axial spondyloarthritis (axSpA) and the self-reported questionnaire Bath Ankylosing Spondylitis Functional Index (BASFI) is recommended for the evaluation. However, it is shown that BASFI may not be sufficiently sensitive to detect changes after physical therapy. Based on BASFI a disease-specific performance-based measure has been developed; the Ankylosing Spondylitis Performance-based Improvement (ASPI). Objectives To compare the proportion of patients with axSpA considered as responders in the performance-based function measure ASPI and the self-reported BASFI after a physical therapy exercise intervention. Methods This study was part of the ESpA-study (Exercise for SpondyloArthritis) which examines the effect of 12 weeks, supervised high intensity exercise intervention. Patients with axSpA were included from 4 centres in Scandinavia. Physical function was assessed with ASPI and BASFI at baseline and after 3 months. The ASAS20 response criteria were used to categorise patients as intra-individual responders or non-responders. In BASFI, patients were classified as responders if they showed an improvement of ≥20% and≥1 unit. In ASPI, patients were classified as responders if they showed an improvement of ≥20% on 1 or more subtest(s) and the absence of deterioration on the potential remaining test. Deterioration was defined as a worsening of ≥20% in 1 or more subtest(s). The proportion of patients categorised as intra-individual (non-) responders was examined with Chi square test. Results A total of 58 patients (intervention n=30, control n=28) with complete data on ASPI and BASFI were included in the analyses, 41% were male, mean age (SD) was 45 (10.7) years, 55% had radiographic axSpA and mean disease activity (ASDAS) (SD) was 2.6 (0.7). In BASFI, a score of Conclusions The performance-based physical function measure ASPI was more sensitive to detect responders than the self-reported measure BASFI according to the ASAS20 response criteria in patients with axSpA after a high intensity exercise intervention. Our findings suggest that the performance-based physical function (ASPI) measure is preferable when evaluating physical function after exercise interventions with physical therapy. Disclosure of Interest None declared