Racial discrimination as a mediator of racial disparities in insomnia disorder

• Authors: Philip Cheng, Henry Ford Health System; Ruby Cuellar, University of Oregon; Dayna Johnson, Emory University; Dayna A. Kalmbach, Henry Ford Health System; Christine L. M. Joseph, Henry Ford Health System; Andrea Cuamatzi Castelan, Henry Ford Health System; Chaewon Sagong, Henry Ford Health System; Melynda D. Casement, University of Oregon; Christopher L. Drake, Henry Ford Hospital
• Journal Title: Sleep Health
• Volume: Volume 6, Number 5
• Publisher: Elsevier | 2020-10-01, Pages 543-549
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.sleh.2020.07.007
• Subjects: Biology, Neuroscience; Health Sciences, Mental Health; Health Sciences, Public Health; Health Sciences, Epidemiology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Neurosciences & Neurology; Insomnia; Health disparities; Discrimination; Severity index; Psychosocial stressors; Health disparities; Sleep disturbances; Mental health; Risk factors; Minority; Adults; Race/ethnicity; Comorbidity

Abstract

Study Objectives Racial and ethnic minorities are more likely to suffer from insomnia that is more severe; however, few studies have examined mechanisms by which racial disparities in severity of insomnia disorder may arise. One potential mechanism for disparities in insomnia severity is perceived discrimination. This study tested discrimination as a mediator in the relationship between race and insomnia. Methods Participants were recruited from communities in the Detroit metropolitan area and were diagnosed with insomnia disorder using the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition). The final sample included 1,458 individuals. Insomnia symptom severity was assessed via the Insomnia Severity Index and self-reported racial discrimination was evaluated using a single item. Racial discrimination was tested as a mediator in the relationship between race and insomnia symptom severity. Individuals were categroized as either White or a racial minority (i.e., non White individuals), with sensitivity analyses examining Black individuals and non-Black racial minority groups. Results Consistent with our hypothesis, racial discrimination was a significant mediator accounting for 57.3% of the relationship between race and insomnia symptom severity. Sensitivity analyses indicated that the indirect effect of racial discrimination was stronger in the non-Black racial minority group compared to Black individuals. Conclusions These results provide support that racial discrimination is likely an important mechanism by which racial and ethnic sleep disparities exist. Implications for prevention, intervention, and treatment of insomnia in racial minorities to reduce health disparities are discussed.