Disease-modifying therapies do not affect sleep quality or daytime sleepiness in a large Australian MS cohort

Background: Poor sleep is common in multiple sclerosis (MS) and may impact daily functioning. The extent to which disease-modifying therapies (DMTs) contribute to sleep outcomes is under-examined. Objective: To compare the effects of DMTs on sleep outcomes in an Australian cohort of people with MS and investigate associations between DMT use and beliefs about sleep problems and daily functioning (social functioning and activity engagement). Methods: Sleep outcomes were assessed using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. DMT use and functioning were self-reported. Results: Of 1,715 participants, 64% used a DMT. No differences in sleep outcomes were detected between participants who did and did not use DMTs, the type of DMT used (lower vs higher efficacy, interferon-β vs other DMTs), the timing of administration, or adherence to standard administration recommendations. Beliefs that DMT use worsened sleep were associated with poorer sleep quality and perceptions that sleep problems interfered with daily functioning. Conclusion: The use of a DMT does not appear to affect self-reported sleep outcomes in people with MS. However, beliefs that DMT use makes sleep worse were associated with poorer sleep quality and increased interference in daily functioning, suggesting a need for education to diminish negative perceptions of DMT use.