Differences in sleep between black and white adults: an update and future directions.

Meta-analyses and other previous reviews have identified distinct ethnic/racial differences in the quantity, quality, and propensity for sleep disorders between black and white adults. The present article reviews the meta-analytic evidence along with recent epidemiological, community, and clinical studies to clarify what is known and not known about sleep differences between these two groups. Black individuals tend to have poorer sleep continuity and quality, excessively short or long sleep duration, greater sleep variability, and greater risk of sleep apnea than white individuals. The data suggest that these differences are attenuated yet persist in the face of several relevant confounders such as socioeconomic status, occupational factors, neighborhood context, and comorbidities. However, little is known about the mechanisms that explain ethnic disparities in sleep. We propose a conceptual model of potential mediators for future testing as well as other questions in need of investigation.