Continuous Step Count Monitoring of Multiple Sclerosis Patients Can Track Disability Progression

Continuous remote step monitoring of patients with multiple sclerosis (MS) is an effective means of revealing clinically pertinent data not captured by standard metrics and indicates that a low step count correlates with disability and the risk of increased disease progression, according to a study published in JAMA.

In this prospective longitudinal cohort study, researchers recruited 95 individuals (59 women and 36 men, mean age, 49.6) from the University of California between June 2015 and August 2016 with relapsing or progressive MS who had the capacity to walk for more than two minutes with or without an assistive monitoring device. Participants were requested to wear a commercially available activity monitor (Fitbit Flex) on their nondominant wrist over the duration of one year and were directed to continue their normal daily routines while their step count was continuously tracked.

Researchers prohibited patients if they experienced a clinical relapse within 30 days, or if they had any musculoskeletal or cardiovascular comorbidities that contributed to ambulatory impairment or lead to an inability to consent or follow study directions. Longitudinal analysis was performed from October 2017 to March 2018 and revised analysis was conducted in December 2018.

Low Steps Associated with Worsening Outcomes

The results indicate a modest reduction in accelerometer use during the one year of the study. Moreover, a decreasing average daily step count during the study was associated with worsening of clinic-based outcomes (Timed 25-Foot Walk, β =−13.09; Timed-Up-and-Go, β =−9.25), and patient-reported outcomes (12-item Multiple Sclerosis Walking Scale, β =−17.96). Furthermore, a decreasing average daily step count occurred even when the Expanded Disability Status Scale (EDSS) score remained stable, and 12 of 25 participants (48%) with a significant decline in average daily step count during the study did not have a reduction on other standard clinic-based metrics.

Overall, participants with a baseline average daily step count below 4,766 had higher odds of clinically significant disability (EDSS score) worsening at one year, adjusting for age, sex, and disease duration (OR=4.01; 95% CI, 1.17 to 13.78).

Results Could be Relevant in Treating MS

“Although there was a modest reduction in the number of people providing valid accelerometer data during the study, adherence to and use of the accelerometer was higher than might be expected from surveying the literature in the general population or among individuals with MS,” said researchers in discussing the study’s results.

Despite noting several study limitations, such as possible missing data from sick patients, the need to conduct research on a larger cohort, and the use of a monitoring device that is already being supplanted by newer devices, researchers remain optimistic about their initial findings.

“These results appear to support the average daily step count as a sensitive and ecologically valid, longitudinal outcome measure in MS. Moreover, the average daily step count could be relevant for targeted intervention in controlled trials as well as in clinical practice in MS and other neurologic disorders.”