AB0558 Three easy tests of physical functioning (aspi) show improvement after anti-tnf therapy, even in asas20 non-responders in ankylosing spondylitis
Authors: S. van Weely, J. Dekker, M. Steultjens, C. van Denderen, M. Nurmohamed, B. Dijkmans, I. van der Horst-Bruinsma
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> In most clinical trials response to anti-TNF therapy is based on the ASAS20% response criteria (ASAS20) [1]. The ASAS20 is based on self-reported questions on physical function (Bath AS Functional Index, BASFI [2]), disease activity, and a pain and a global patient assessment. However, self-reported measures can be influenced by over- or underestimation. In an effort to find more objective outcome measures, eight performance-based tests were developed based on items of the BASFI. The tests provided information on physical functioning in addition to the BASFI and showed improvement in ASAS20 non-responders after anti-TNF therapy. However, performing all eight tests might be cumbersome in daily clinical practice. <h3>Objectives</h3> To find a limited set of quick and easy applicable performance-based tests for daily clinical practice that are reliable and reflect improvement in physical functioning after anti-TNF therapy in ASAS20 non-responders. <h3>Methods</h3> A test-retest design was used to evaluate reliability (n=65). A longitudinal design was applied to evaluate improvement in performance-based physical functioning after three months of anti-TNF therapy (n=82). The tests that showed an adequate reliability and the largest proportion of patients with an improved performance-based physical functioning were selected. These tests were combined into a new criterion for improvement in physical functioning (AS Performance-based Improvement, ASPI). The ASPI was used to establish the proportion of patients with an improved physical functioning that might be missed by using the ASAS20 response. <h3>Results</h3> Reliability for all tests was adequate to excellent (ICC's 0.73 - 0.96). The tests for bending, putting on socks and getting up from the floor showed the largest proportion of improved patients. The combination of these three test showed improved physical functioning in 73% of the ASAS20 responders (i.e. n=40/82= 49% total group) and 56% of the ASAS20 non-responders (i.e. n=15/82 =18% total group). For these tests only a stopwatch, 15 minutes of time, a shelf or table, six pens, a pair of socks, a chair and mat are necessary. <h3>Conclusions</h3> The tests for bending, putting on socks and getting up from the floor are recommended for use in daily practice, because they are reliable, quick and easy to perform. Moreover, the combination of these tests (i.e. ASPI) showed an improved physical functioning after TNF therapy in 56% of the non-responders (i.e. 18% total group). The ASPI might have an important additional value next to the ASAS20 in the evaluation of the effect of anti-TNF treatment. <h3>References</h3> Calin A, Garrett S, Whitelock H, Kennedy LG, O'Hea J, Mallorie P, et al. A new approach to defining functional ability in ankylosing spondylitis: the development of the Bath Ankylosing Spondylitis Functional Index. J Rheumatol 1994; 21:2281-5. Anderson JJ, Baron G, van der Heijde D, Felson DT, Dougados M. Ankylosing Spondylitis assessment group preliminary definition of short-term improvement in ankylosing spondylitis. Arthritis Rheum 2001; 44:1876-86. <h3>Disclosure of Interest</h3> None Declared