Testing the construct validity of real-world digital mobility outcomes in multiple sclerosis

Brittain G, Long M, Buckley E, Becker C, Buekers J, de las Heras M, Armengol C, Koch S, Braun J, Caufield B, Comi G, Dalla Costa G, Frei A, Gaßner H, Ionescu A, Leocani L, Rochester L, Rothhammer V, Singleton D, Stuerner KH, Paling D, Padmakumari Sivaraman Nair K, Majid A, Brichetto G, Vereijken B, Lanfranchi V, Jansen CP, Sutcliffe L, Del Din S, Neatrour I, Cereatti A, Maetzler W, Hansen C, Rooks D, Sharrack B, Garcia-Aymerich J (2026)

Publication Type: Journal article

Publication year: 2026

Journal

DOI: 10.1177/13524585261464537

Abstract

Background: Wearable devices can measure real-world mobility and generate metrics known as digital mobility outcomes (DMOs). For people with multiple sclerosis (pwMS), these DMOs have not been clinically validated. This study aimed to evaluate the construct (convergent, divergent, and known groups) validity of a comprehensive panel of 24 DMOs in pwMS. Methods: PwMS were recruited to the Mobilise-D Clinical Validation Study, which involved 7-days of real-world mobility monitoring with a lower-back-worn wearable device. DMOs of walking amount, pattern, pace, rhythm, and variability domains were assessed. Convergent validity was evaluated against established clinical constructs (Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk, Multiple sclerosis (MS) Walking Scale-12, and Patient-Determined Disease Steps) using a priori hypotheses. Divergent validity was tested against systolic blood pressure. Known-groups validity was assessed across three EDSS strata. An expert panel completed a standardised consensus process. Results: We included 556 participants: 65% women, mean (SD) age of 52.3 (10.7) years, and median (p25–p75) EDSS 5 (4–6). Convergent, divergent, and known-groups validity were supported for 19, 24, and 23 DMOs, respectively. Nineteen DMOs, covering all domains, reached consensus agreement. Conclusion: This study confirms the construct validity of 19 DMOs across all walking domains in pwMS, supporting their use in clinical research and practice. www.isrctn.com/ISRCTN12051706.

Authors with CRIS profile

Involved external institutions

University of Sheffield United Kingdom (GB) NTNU Trondheim - Norwegian University of Science and Technology Norway (NO) NIHR Sheffield Biomedical Research Centre (BRC) United Kingdom (GB) Robert Bosch GmbH Germany (DE) Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP) Spain (ES) Universität Basel Switzerland (CH) Novartis Institutes for BioMedical Research, Inc. United States (USA) (US) University of Zurich / Universität Zürich (UZH) Switzerland (CH) University College Dublin (UCD) Ireland (IE) Casa di Cura Igea Italy (IT) Ospedale San Raffaele (früher: Centro San Raffaele del Monte Tabor Foundation) Italy (IT) École Polytechnique Fédérale de Lausanne (EPFL) Switzerland (CH) Università Vita-Salute San Raffaele (UniSR) Italy (IT) Newcastle University United Kingdom (GB) Universitätsklinikum Schleswig-Holstein (UKSH) Germany (DE) AISM Liguria Region Rehabilitation Service / Servizio di Riabilitazione Liguria Italy (IT) Ruprecht-Karls-Universität Heidelberg Germany (DE) Politecnico di Torino / Polytechnic University of Turin Italy (IT)

How to cite

APA:

Brittain, G., Long, M., Buckley, E., Becker, C., Buekers, J., de las Heras, M.,... Garcia-Aymerich, J. (2026). Testing the construct validity of real-world digital mobility outcomes in multiple sclerosis. Multiple sclerosis journal. https://doi.org/10.1177/13524585261464537

MLA:

Brittain, Gavin, et al. "Testing the construct validity of real-world digital mobility outcomes in multiple sclerosis." Multiple sclerosis journal (2026).

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