Neighborhood social vulnerability as a mediator of racial disparities in insomnia severity.

Study objectives: Recent data has indicated that Black Americans experience more severe insomnia compared to their White counterparts. Although previous studies have identified psychosocial mechanisms driving this disparity, little is known about the structural determinants of insomnia disparities. This study tested neighborhood social vulnerability as a mechanism driving Black-White disparities in insomnia severity in the United States.

Methods: Participants with a previous diagnosis of insomnia (N = 196) reported their race and insomnia severity (Insomnia Severity Index). As a measure of the neighborhood environment Social Vulnerability Index was calculated by geocoding home address at the time of participation to the respective census tract from the 2020 US Census. A mediation analysis tested the indirect effect of the Social Vulnerability Index between race and insomnia severity.

Results: Black participants reported worse insomnia severity compared to White participants. Black participants also had 3.3 times the odds of living in neighborhoods with higher social vulnerability compared to White participants, with a group median difference of 0.26 percentile points (scale 0 to 1). As hypothesized, results revealed a significant indirect effect of the Social Vulnerability Index, which accounted for 31.1% of the variance between race and insomnia severity.

Conclusion: Living in a socially vulnerable neighborhood environment may be a mechanism driving racial disparities in insomnia severity. Interventions that consider structural determinants of health, including community-based and policy-level interventions could have an enhanced impact on addressing insomnia and its public health consequences.