Restless legs syndrome and sleep quality in patients with multiple sclerosis: A moderated mediation model of anxiety, fatigue, and disease duration.

AIMS: Restless Legs Syndrome (RLS) is common among individuals with Multiple Sclerosis (MS) and frequently co-occurs with poor sleep quality, fatigue, and psychological distress. Understanding how these symptoms are interrelated may inform nursing assessment and symptom management. This study examined the association between RLS severity and sleep quality in individuals with MS and explored a theory-driven moderated mediation model in which anxiety and fatigue were examined as indirect correlates, and disease duration as a moderating factor.

METHODS

A cross-sectional correlational study was conducted with 110 individuals diagnosed with MS, recruited from a governmental hospital outpatient clinic in Egypt. Data were collected using validated self-report measures of RLS severity, sleep quality, anxiety, fatigue, and disease duration. Structural equation modeling was used to examine direct and indirect associations among variables, following the STROBE checklist.

RESULTS

Greater RLS severity was significantly associated with poorer sleep quality (β = 0.31, p < 0.001), higher anxiety (β = 0.42, p < 0.001), and greater fatigue (β = 0.28, p = 0.001). Anxiety and fatigue statistically accounted for a significant portion of the association between RLS severity and sleep quality. Conditional indirect associations indicated that these relationships were stronger among individuals with longer MS duration (>5 years).

CONCLUSION

RLS severity is associated with poorer sleep quality in individuals with MS, both directly and indirectly through anxiety and fatigue, with these indirect associations varying as a function of disease duration. Although exploratory and cross-sectional, these findings highlight the importance of comprehensive nursing assessment and integrated symptom management approaches addressing RLS, anxiety, and fatigue to support sleep quality and overall well-being in MS care.