A systematic review of acculturation and sleep health among adult immigrants in the United States.

The United States (US) has more immigrants than any other country in the world, with an estimated 44 million non-US-born individuals residing in the country as of 2018. Previous studies have linked US acculturation to both positive and negative health outcomes, including sleep. However, the relationship between US acculturation and sleep health is not well understood. This systematic review aims to identify and synthesize scientific studies on acculturation and sleep health among adult immigrants in the US. A systematic search of the literature was performed in PubMed, Ovid MEDLINE, and Web of Science in 2021 and 2022 with no date limiters. Quantitative studies published anytime in a peer-reviewed journal in English among an adult immigrant population with an explicit measure of acculturation and a sleep health dimension, sleep disorder, or daytime sleepiness measure were considered for inclusion. The initial literature search yielded 804 articles for review; after removing duplicates, applying inclusion and exclusion criteria, and searching reference lists, 38 total articles were included. We found consistent evidence that acculturative stress was associated with worse sleep quality/continuity, daytime sleepiness, and sleep disorders. However, we discovered limited consensus on the association of acculturation scales and acculturation proxy measures with sleep. Our review demonstrated that compared to US-born adult populations, there is a high prevalence of adverse sleep health among immigrant populations, and acculturation likely plays an important role in shaping this disparity, particularly through acculturative stress.