JMIR Publications

ABSTRACT

Background:

Tools for measuring clinical disability status in people with multiple sclerosis (MS) are limited. Accelerometry objectively assesses physical activity and circadian rhythmicity profiles in the real-world environment and may potentially distinguish levels of disability in MS.

Objective:

To determine if accelerometry can detect differences in physical activity and circadian rhythmicity patterns between relapsing-remitting MS (RRMS) and progressive MS (PMS).

Methods:

This study represents an analysis of the baseline data from the prospective HEAL-MS study. Participants were divided into three groups based on the Expanded Disability Status Scale (EDSS) criteria for sustained disability progression: RRMS-Stable, RRMS-Suspected progression, and PMS. Baseline visits occurred between January 2021 and March 2023. Clinical outcome measures were collected by masked examiners. Participants wore the GT9X Link Actigraph on their non-dominant wrists for two weeks.

Results:

A total of 253 participants were included: 86 RRMS-Stable, 82 RRMS-Suspected progression, and 85 PMS. Compared to RRMS, PMS participants had lower total activity counts (β: -0.32 [95% CI: -0.61, -0.03]), lower time spent in moderate-to-vigorous physical activity (β: -0.01 [-0.02, -0.004]), higher active-to-sedentary transition probability (β: 5.68 [1.86, 9.50]), lower amplitude (β: -0.0004 [-0.0008, -0.0001]), lower MESOR (β: -0.0009 [-0.002, -0.0002]), higher intra-daily variability (β: 4.64 [1.45, 7.84]), and lower inter-daily stability (β: -4.43 [-8.77, -0.10]). No significant differences were detected between the two RRMS subtypes except for lower relative amplitude in those with suspected progression.

Conclusions:

Accelerometry detected differences in physical activity patterns between RRMS and PMS. Longitudinal follow-up is underway to assess the potential for accelerometry to detect disability progression.