# MScope: A Reliable Battery for Functional Status Assessment in Multiple Sclerosis
## 4 Discussion
The reliability and validity of the 5 RSTST have recently been confirmed, demonstrating high reliability (ICC = 0.99) and excellent intra- and inter-rater reliability for assessing muscle strength when administered remotely in MS [20]. Moreover, similar studies on patients with neurodegenerative diseases have yielded comparable findings regarding the intra-day reliability and test-retest reproducibility of the 5 RSTST. For example, [PERSON] et al. [21] reported intra-day ICCs between 0.97 and 0.99 in individuals with Parkinson's disease, while [PERSON] et al. [19] reported test-retest reproducibility between 0.76 and 0.98 in stroke patients. Differences between our results and previous studies could be due to our method of calculation. Instead of simply recording the time taken to complete five repetitions [20], as is common in earlier studies, we implemented a more precise approach that incorporates each patient's anthropometric characteristics to calculate average power output during the test [28]. This algorithm, based on the mean time to complete the five repetitions, may slightly influence the results, and explain the observation of only low reproducibility in our study, despite the test demonstrating high intra- and inter-day ICCs (Tables 1 and 2). Regarding the 60 STST, there is no previous scientific evidence available on the reliability of this test in PwMS. However, the reliability of the same test with a duration of 30 seconds, rather than 60 seconds, has been analyzed in PwMS, demonstrating an ICC of 0.983 [37]. This finding aligns well with our results and supports the 60 STST as a valid, feasible, and reliable tool for assessing functional capacity and muscular endurance in PwMS. On the other hand, as gait speed has been associated with quality of life in patients with MS and has been widely assessed through the MSWS-12 test, it is one of the most commonly measured indicators for categorizing frailty levels in this population [38]. Among the tests frequently used for this purpose is the T25 FW (i.e., 7.6 m distance), which has shown excellent test-retest reliability (ICC = 0.98) [39], establishing associations between increases in walking time and factors such as age, disability, disease type, and disease duration [39]. However, this study is the first to analyze the reliability of the 10 MWT in PwMS, showing similar results with the timed 25-foot walking test. In addition, it demonstrates similarly high reproducibility and strong validity, with results aligning closely with those observed in patients with other neurological conditions, such as Parkinson's disease (ICC = 0.92) [40], or in healthy older adults (ICC = 0.98) [41]. Hence, the 10 MWT has significant utility for PwMS, as it provides a simple, yet effective measure to assess functional mobility, balance, and gait, allowing clinicians to monitor disease progression and adjust rehabilitation protocols accordingly [38]. Regarding the 6 MWT, previous studies demonstrated excellent reliability (ICC = 0.95) in PwMS, positioning this test as a valid approach to estimate functional capacity and cardiovascular fitness [34; 42; 43]. Our study found a similarly high reliability (ICC = 0.94), further supporting its applicability in this population. Including the 6 MWT in our battery of tests allows us to assess a critical aspect of functional mobility, as it correlates with daily life activity levels and can effectively gauge changes over time or in response to interventions [44]. However, a limitation of our study was the inability to evaluate intra-day reliability due to the potentially exhaustive nature of the 6 MWT, as it was performed only once per laboratory visit to prevent potential fatigue in participants. It is important to note that, despite the acceptable reliability of the data, statistically significant differences were observed between the mean results of the two test days for the TUG test, 60 STST, 10 MWT, and 6 MWT.