Clinimetric Validation of the Assessment of Spondyloarthritis International Society Health Index in Patients With Radiographic Axial Spondyloarthritis in Ixekizumab Trials

Uta Kiltz; Désirée van der Heijde; Annelies Boonen; Lianne S Gensler; Theresa Hunter Gibble; Jiaying Guo; Hilde Carlier; Juergen Braun

doi:10.3899/jrheum.220244

Clinimetric Validation of the Assessment of Spondyloarthritis International Society Health Index in Patients With Radiographic Axial Spondyloarthritis in Ixekizumab Trials

J Rheumatol. 2023 Jun;50(6):754-762. doi: 10.3899/jrheum.220244. Epub 2023 Feb 1.

Authors

Uta Kiltz¹, Désirée van der Heijde², Annelies Boonen³, Lianne S Gensler⁴, Theresa Hunter Gibble⁵, Jiaying Guo⁶, Hilde Carlier⁶, Juergen Braun¹

Affiliations

¹ U. Kiltz, MD, J. Braun, MD, Rheumazentrum Ruhrgebiet, Herne, and Ruhr-Universität Bochum, Bochum, Germany.
² D. van der Heijde, MD, PhD, Leiden University Medical Center, Leiden, the Netherlands.
³ A. Boonen, MD, PhD, Maastricht University Medical Center, and Caphri Research Institute, Maastricht University, Maastricht, the Netherlands.
⁴ L.S. Gensler, MD, University of California, San Francisco, San Francisco, California, USA.
⁵ T. Hunter Gibble, PhD, J. Guo, MS, H. Carlier, MD, Eli Lilly and Company, Indianapolis, Indiana, USA. hunter_theresa_marie@lilly.com.
⁶ T. Hunter Gibble, PhD, J. Guo, MS, H. Carlier, MD, Eli Lilly and Company, Indianapolis, Indiana, USA.

PMID: 36725056
DOI: 10.3899/jrheum.220244

Abstract

Objective: To assess test-retest reliability, construct validity, known groups discrimination, and responsiveness of the Assessment of the SpondyloArthritis international Society Health Index (ASAS HI) to evaluate functioning, disability, and health in patients with radiographic axial spondyloarthritis (r-axSpA).

Methods: Data were generated from 2 randomized, placebo-controlled, active-controlled phase III ixekizumab studies (COAST-V, N = 341; COAST-W, N = 316). Assessments included the following: test-retest reliability (ie, intraclass correlation coefficients [ICCs] between ASAS HI scores at screening and baseline), construct validity (ie, Spearman correlation with standard r-axSpA outcome measures), known groups discrimination (ie, 1-way ANOVA comparing the ASAS HI with different disease activity categories, measured by the Ankylosing Spondylitis Disease Activity Score [ASDAS]), and responsiveness (ie, Spearman correlation between changes in the ASAS HI and changes in the Bath Ankylosing Spondylitis Functional Index [BASFI], the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], the ASDAS, and the Patient Global Assessment [PtGA] as well as ANOVA comparing changes in the ASAS HI with various responder categories).

Results: The ICC for test-retest reliability was 0.78 for COAST-V and 0.76 for COAST-W, indicating adequate agreement. Moderate-to-large correlations (r = 0.40-0.61) were observed between the ASAS HI and the BASDAI. Statistically significant differences (all P < 0.001) between mean ASAS HI scores were observed for subgroups based on ASDAS-defined disease activity categories at baseline and week 16. Moderate-to-large correlations existed between changes in the ASAS HI and the BASFI, BASDAI, ASDAS, and PtGA from baseline to week 16. The ASAS HI differentiated statistically (P < 0.001) between ASAS, BASDAI, and ASDAS response groups.

Conclusion: The ASAS HI demonstrated reliability, construct validity, known groups discrimination, and responsiveness in adults with r-axSpA in 2 clinical trials.

Keywords: ankylosing spondylitis; reproducibility of results; spondyloarthropathy.

Publication types

Clinical Trial, Phase III
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Humans
Quality of Life
Reproducibility of Results
Severity of Illness Index
Spondylarthritis* / diagnostic imaging
Spondylarthritis* / drug therapy
Spondylitis, Ankylosing*

Substances

ixekizumab