Background: Sleep disturbances are common, underdiagnosed and have negative consequences for people with multiple ­sclerosis.

Objective: Gather information about the prevalence of poor sleep quality and sleep disturbances in Icelanders with multiple ­sclerosis.

Method: A cross-sectional self-report survey. Population: Icelanders with multiple sclerosis. Sample: People with multiple sclerosis, who were on the online mailing list or had access to Facebook groups of the Multiple-Sclerosis-Society in Iceland. An electronic link with background questions and 4 questionnaires was available to participants. Questionnaires: The Pittsburgh- Sleep-Quality-Index (PSQI), the Insomnia-Severity-Index, the STOP-Bang-questionnaire and 5 diagnostic criteria for restless legs syndrome. Questionnaires were used to screen for poor sleep quality, and 7 different factors that can cause disturbed sleep. Data was analyzed with SPSS version 25.

Results: Almost 40% of Icelanders with multiple sclerosis participated or 234 persons. Mean age was 47 years (range 20-92) and 77% were female. The prevalence of poor sleep quality (PSQI>5), was 68%. The factors that most often caused dis­turbed sleep were; bathroom breaks (39%), pain (37%), insomnia symptoms (30%) and sleep apnea symptoms (24%). Majority of participants or 79% had at least one sleep disturbance and on average they had close to two. Insomnia symptoms were strongly related to poor sleep quality.

Conclusion: High prevalence of poor sleep quality and sleep disturbances in people with multiple sclerosis needs to be addressed. PSQI can be used to screen for poor sleep quality and to assess whether further sleep evaluation is needed. Screening, diagnosis and treatment of insomnia should be implemented.

Table I   Insomnia, sleep apnea and restless legs syndrome. Prevalence of symptoms compared to prevalence of diagnosis by a physician

Table II  Prevalence of disturbed sleep because of bathroom breaks, pain, heat and cold

Tabel III  Linear regression. Dependent variable PSQI. Predictors: age, sex, bathroom break, pain, score on Insomnia-Severity-Index, score on STOP-Bang-questionnaire and the five diagnostic criteria for restless-legs-syndrome

Figure I  Prevalence of and overlap between increased risk of insomnia, obstructive sleep apnea and restless legs syndrome. More than half of participants (n=188) or 52.6% had scores that indicated increased risk of insomnia, restless legs syndrome and/or obstructive sleep apnea. Thereof 2.7% had scores that indicated increased risk for all three

Figure II Prevalence of and overlap between sleep disturbances because of pain, the need to use the bathroom and insomnia symptoms. Pain, the need to use the bathroom and insomnia symptoms were the most common factors to cause disturbed sleep and affected 63.4% of participants (n=216). Thereof 11.6% had disturbed sleep because of all three factors