Sleep Quality, Dysfunctional Sleep Beliefs, and Health-Related Quality of Life and Functioning in People With Multiple Sclerosis

Background: People with multiple sclerosis (MS) are more prone to sleep disturbances than the general population. Poor sleep is associated with diminished health-related quality of life and functioning (HRQOL/F) in people with MS and may trigger unhelpful thoughts and beliefs about sleep. This study aimed to examine the relationship between self-reported sleep quality, dysfunctional sleep beliefs, and HRQOL/F in a sample of people with MS. Methods: Participants (N = 200) completed the Pittsburgh Sleep Quality Index (PSQI), the Dysfunctional Beliefs and Attitudes about Sleep Scale-16 (DBAS-16), and HRQOL/F patient-reported outcome measures (PROMs). Separate multivariable linear regressions were modeled, each including 1 PROM as the dependent variable. For each PROM, 2 models were fit: one with the PSQI score as the predictor and one with the DBAS-16 score. All models included demographic and/or clinical factors as covariates. Two-way interactions between each PSQI and DBAS-16 score and each demographic and/or clinical factor were added to the models. Mediation analysis was performed where each PROM was the outcome, the PSQI score was the predictor, and the DBAS-16 score was the mediator. Results: Worse self-reported sleep quality and a greater degree of dysfunctional sleep beliefs were significantly associated with worse t scores for global HRQOL/F physical and mental health outcomes and several Quality of Life in Neurological Disorders (Neuro-QoL) scales. Dysfunctional sleep beliefs significantly mediated the association between PSQI and HRQOL/F mental health outcomes and several Neuro-QoL scales, and significant interactions between PSQI, DBAS-16, and demographic/clinical factors were revealed. Conclusions: Sleep quality and dysfunctional sleep beliefs are important correlates of HRQOL/F in people with MS. In clinical settings, thorough assessment and intervention targeting these factors are warranted.