Ab0937 Improvements in Disease Activity and Functional Impairment After Multimodal Spa Therapy in Ankylosing Spondylitis Patients

Background: Comprehensive, multidisciplinary care is crucial for effective ankylosing spondylitis (AS) management and patient well-being. Despite its recognized importance, the amount of evidence on the role of multimodal therapies in improving disease activity and functional ability is limited. Even less is known regarding the course of such outcomes after more traditional multimodal approaches like spa therapy combined with e.g. physical therapy and exercises, as data are rarely collected systematically in a real-life setting after such interventions. Objectives: To explore disease activity (measured by the Bath Ankylosing Spondylitis Disease Activity Index - BASDAI) and functional impairment (measured by the Bath Ankylosing Spondylitis Functional Index - BASFI) in AS patients who received multimodal spa therapy in the Austrian Gastein valley over a course of 9 months after treatment. Methods: Longitudinal analyses were conducted using prospectively collected register data from the ongoing "Radon indication registry". AS patients who were enrolled in the registry by participating spa physicians completed paper based questionnaires directly before (T0), directly after (T1), and 3 (T2), 6 (T3) and 9 (T4) months after multimodal spa therapy. Questionnaires included information on BASDAI, BASFI, age, sex and body mass index (BMI). Treatment consisted of multimodal spa therapy (average duration 17.5 days) with a set of diverse therapeutic modalities, such as physical exercise, mud therapy, ergometry, low-dose radon balneo- and/or speleotherapy, etc. Mixed-effects linear regression models explored the association between timepoint of measurement and BASDAI and BASFI scores, respectively. Timepoint, age, sex, and BMI were incorporated as fixed factors in the model and patient ID was included as a random factor. Linear margins based on the fixed model portion were predicted for BASDAI and BASFI at each timepoint. P-values ≤0.05 were considered statistically significant. A change of 17.5% in BASFI-scores and of 22.5% in BASDAI-scores was considered clinically relevant. Results: A total of 249 AS patients who had completed questionnaires at all specified time points with no missing values in any of the considered variables was included in the analyses. The sample comprised 106 women (42.57%), the mean age was 52.14 (SD 10.20) and the average BMI was 26.64 (SD 4.27). Compared to T0, BASFI and BASDAI improved significantly until 6 and 9 months, respectively (Table 1). The predicted BASDAI scores at T0, T1, T2 and T3 were 2.99 (95% CI 2.77;3.21), 2.31 (95% CI 2.08;2.53), 2.38 (95% CI 2.15;2.61) and 2.69 (95% CI 2.46;2.92). At T4 the score was higher than at T0 (3.04 (95%CI 2.81; 3.28)). Compared to T0, the BASDAI score at T1 reflected a clinically relevant change of approximately 23%. The predicted BASFI scores at T0, T1, T2, T3 and T4 were 4.09 (95% CI 3.88;4.31), 2.71 (2.49;2.94), 2.83 (95% CI 2.60;3.06), 3.24 (95% CI 3.01;3.46) and 3.59 (95% CI 3.36;3.82). Compared to T0, the BASFI scores at T1, T2 and T3 reflected a clinically relevant change of approximately 34%, 31% and 21%, respectively (Figure 1). Conclusion: The current study reveals that AS patients who received multimodal spa-therapy including low-dose radon balneo- and/or speleotherapy show significantly and clinically relevant improvements in disease activity and functional impairment. It may therefore be considered a valuable (complementary) treatment option for AS. The results might also assist in the determination of adequate treatment intervals to obtain and maintain stable outcomes. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.