The Association Between Sleep Disturbance and Health Outcomes in Chronic Whiplash-associated Disorders: A Series of Mediation Analyses

Objectives: To investigate the association between sleep disturbance and clinical features of chronic whiplash-associated disorders (WAD). We also aimed to use a bootstrapped mediation analysis approach to systematically examine both direct and indirect pathways by which sleep disturbance may affect chronic pain and functional status.

Materials and methods: One hundred sixty-five people (63% female) with chronic WAD and not taking medications for sleep disturbance completed questionnaires evaluating sleep disturbance, pain intensity, pain interference, disability, physical and mental health quality of life, stress, anxiety, depression, pain catastrophizing, and posttraumatic stress severity.

Results: Greater sleep disturbance was associated with increased duration of symptoms, higher levels of pain and disability, higher levels of emotional distress and pain catastrophizing, and functional impairment (reduced health-related quality of life). Mediation analyses demonstrated that sleep disturbance influenced chronic pain intensity and interference through both direct and indirect associations inclusive of stress, anxiety, and pain catastrophizing. Similarly, sleep disturbance was associated with higher levels of disability and poor health-related quality of life, both directly and also through its negative association with pain intensity and interference.

Discussion: Sleep disturbance in chronic WAD was associated with worse health outcomes and demonstrated both direct and indirect effects on both chronic pain and function.