Gait Characteristics Harvested during a Smartphone-Based Self-Administered 2-Minute Walk Test in People with Multiple Sclerosis: Test-Retest Reliability and Minimum Detectable Change

• Published in: Sensors (Basel, Switzerland) Vol. 20; no. 20; p. 5906
• Main Authors: Bourke, Alan K., Scotland, Alf, Lipsmeier, Florian, Gossens, Christian, Lindemann, Michael
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.10.2020; MDPI
• Subjects: 2-minute walk test; Accelerometers; Algorithms; Data analysis; Female; Gait; Humans; Laboratories; MDC; Multiple sclerosis; Multiple Sclerosis - diagnosis; Reproducibility of Results; Sensors; Smartphone; Smartphones; test-retest reliability; Walk Test; Walking; Wavelet transforms; smartphone; 2-minute walk test; gait; multiple sclerosis; SEM; wearable sensors; test-retest reliability; MDC
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s20205906

The measurement of gait characteristics during a self-administered 2-minute walk test (2MWT), in persons with multiple sclerosis (PwMS), using a single body-worn device, has the potential to provide high-density longitudinal information on disease progression, beyond what is currently measured in the clinician-administered 2MWT. The purpose of this study is to determine the test-retest reliability, standard error of measurement (SEM) and minimum detectable change (MDC) of features calculated on gait characteristics, harvested during a self-administered 2MWT in a home environment, in 51 PwMS and 11 healthy control (HC) subjects over 24 weeks, using a single waist-worn inertial sensor-based smartphone. Excellent, or good to excellent test-retest reliability were observed in 58 of the 92 temporal, spatial and spatiotemporal gait features in PwMS. However, these were less reliable for HCs. Low SEM% and MDC% values were observed for most of the distribution measures for all gait characteristics for PwMS and HCs. This study demonstrates the inter-session test-retest reliability and provides an indication of clinically important change estimates, for interpreting the outcomes of gait characteristics measured using a body-worn smartphone, during a self-administered 2MWT. This system thus provides a reliable measure of gait characteristics in PwMS, supporting its application for the longitudinal assessment of gait deficits in this population.