The relationship between insomnia and disability in workers with mild traumatic brain injury/concussion: Insomnia and disability in chronic mild traumatic brain injury

Aim/background: The principal aim of this study was to, for the first time, examine the relationship between insomnia and perceived disability among workers with mild traumatic brain injury (mTBI)/concussion.

Patients/methods: A cross-sectional study was conducted at the Workplace Safety and Insurance Board Clinic of the largest rehabilitation teaching hospital in Canada. Data from questionnaires, insurer records and clinical investigations were analysed. The Insomnia Severity Index measured the primary independent variable, and the Sheehan Disability Scale measured disability outcomes, classified as 'mild/moderate' or 'marked/extreme'. Two-sided t-tests and Chi-squared tests were used for bivariate associations. A binomial logistic regression model was fit using previously identified variables.

Results: The sample comprised 92 workers (45.1 ± 9.9 years old, 61% male) with mTBI/concussion at median time 196 days after injury. When compared with workers reporting lower disability, workers with higher disability were found with more severe insomnia, depression, anxiety and pain. In the multivariable analysis, the odds of reporting higher global disability increased with increasing insomnia and pain [adjusted odds ratio (OR) 1.16 (95% CI 1.03-1.31) and 1.117 (95% CI 1.01-1.24), respectively]. Insomnia was the only significant covariate in a fully adjusted work disability model. None of the variables studied were statistically significant in the social and family life disability models.

Conclusions: Greater attention should be given to the diagnosis and management of insomnia in persons with mTBI/concussion.