Racial disparities and sleep among preschool aged children: a systematic review.

Sleep disorders and sleep insufficiency are common among preschool-aged children. Studies among school-aged children show disordered sleep is often more prevalent among racial minority groups. The primary aim of this systematic review was to critically appraise empirical data to elucidate the relationship between race and key sleep variables among children aged 2 to 5 years old. By systematically searching PubMed, Web of Science, and EBSCO databases, we identified empirical research articles conducted in the United States that investigate this relationship. We searched for variables relevant to (1) insufficient sleep duration, (2) poor sleep quality, (3) irregular timing of sleep, including sleep/wake problems and irregular bedtime onset and wake times (4) and sleep/circadian disorders. Nine studies satisfied the criteria for inclusion: five investigated nocturnal sleep duration, five investigated bedtime-related variables, four investigated daytime sleep (napping), three investigated total sleep, two investigated sleep quality, and one investigated wake times. Four studies specifically addressed racial and demographic differences in sleep variables as the primary aim, while the remaining five contained analyses addressing racial and demographic differences in sleep as secondary aims. Non-Hispanic white, white, or European-American race was used as the reference category in all studies. The results provided consistent evidence that white, non-Hispanic children were more likely to go to bed earlier and more regularly, have longer nocturnal sleep, and nap less than most racial and ethnic minorities. Combined, this literature presents a compelling narrative implicating race as an important factor in sleep patterns among a preschool age population.