Limitations
RRMS
MINOR, DISEASE, RELAPSING REMITTING MULTIPLE SCLEROSIS
The study is limited by the power to detect differences between MBSI-I and SH due to the low number of participants and the higher number of dropouts in the MBSI-I groups. This was partly compensated by the crossover of 10 SH participants into the extended MBSI-I cohort. MBSR programs require significant commitment of time and energy. However, this introduces possible carryover effects from the combined treatment. Perhaps, incorporating make up mindfulness classes into the protocol would help retain participants. There may also be inherent limitations with in-person mindfulness training for PWMS who have significant physical impairments and low energy reserves.The study was not designed to differentiate the effects of mindfulness on PWMS by subtype of MS, e.g., relapsing remitting or progressive forms, or disease severity. We did not collect data on MS subtype, and would not have had the power to analyze outcomes based on this parameter. It can be inferred, based on the relatively low EDSS scores, that the participants had relapsing remitting multiple sclerosis (RRMS). Given that this is a preliminary study, we did not have the power to analyze outcomes based on MS subtypes or impairment. However, future studies might collect this data for analysis.Another set of issues are raised by the use of consumer wrist band actigraphy to measure sleep. These devices are not designed for clinical research studies. While there are benefits of using wrist actigraphy, there also exists potential errors in validity, accuracy and reliability compared with PSG, considered the gold standard for sleep assessment [A final challenge in our study was gaps in data collection from some participants as not all wore their Fitbits™ Charge 2 devices consistently or had technical issues uploading their data. Fortunately, this only required minor adjustments to the time intervals used in the data analysis as described in the 