Table 2.

Summary of systematic review on acculturation and sleep health and sleep disorders in adult immigrant populations in the United States by measure of acculturation.

Study and Designa	Study Population (n)	Acculturation Measure	Sleep Outcome	Study Resultsb
1. Acculturation Scales
Song et al. 2022 [45] Cross-sectional	Older Korean immigrants living in two large predominantly Korean communities in southern California (n=43)	1) SAS-K: 12-item tool based on the SASH measuring language use, media, and ethnic social relations	1) Sleep quality: PSQI, 19-item questionnaire designed to measure self-reported sleep quality during the previous month	→ No significant differences in sleep quality by acculturation level
Barajas-Gonzalez et al. 2021 [47] Cross-sectional	Bangladeshi immigrant parents living in New York City (n=73)	1) Abbreviated Multidimensional Acculturation Scale: measure of English competence assessed using the language competence subscale	1) Sleep problems: PROMIS, measuring sleep disturbances over the past seven days	↑ Increase in parental English competence was associated with a decrease in reported sleep problems (β=−0.78, SE=0.33)
González et al. 2021 [48] Cross-sectional	Hispanic/Latino adults with moderate to severe OSA in four major metropolitan areas (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA) as part of HCHS/SOL (n=1,605)	1) SASH: 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations	1) Sleep phenotype class: three latent classes (minimally symptomatic, excessive sleepiness, disturbed sleep) of five common OSA symptoms and four comorbidities	↓ Minimally symptomatic class, vs. excessive sleepiness and disturbed sleep classes, was the least acculturated group
Ghani et al. 2020 [42] Cross-sectional	Mexican adults living along the U.S.-Mexico border (n=100)	1) ARSMA-II: measure of language use and ethnic identity and interaction comprised of a 17-item questionnaire on Mexican cultural orientation and a 13-item questionnaire on Anglo cultural orientation	1) Insomnia: ISI, a 7-item instrument which assesses the nature, severity, and impact of insomnia 2) Daytime sleepiness: ESS, an 8-item questionnaire that asks respondents to rate their likelihood of falling asleep in eight different contexts 3) Sleep quality: PSQI, 19-item questionnaire designed to measure self-reported sleep quality during the previous month 4) Sleep duration: Sleep Timing Questionnaire (STQ), a questionnaire to assess weekday and weekend sleep duration and validated against a prospective sleep diary 5) Sleep efficiency: weekday and weekend sleep efficiency calculated from values in the STQ 6) Sleep apnea risk: assessed using the Multivariable Apnea Prediction index	→ No associations between Mexican acculturation and any of the sleep outcomes ↓ Increasing levels of Anglo acculturation was associated with less sleep on weekends (β=−41.07, 95% CI: −73.6, −58.49), lower weekend sleep efficiency (β=−4.26, 95% CI: −7.09, −1.43), worse sleep quality (β=1.13, 95% CI: 0.42-1.84), more insomnia (β=1.32, 95% CI: 0.44-2.20), and increased risk for sleep apnea (β=5.57. 95% CI: 1.64-9.49) in models that adjusted for age, sex, and education
Karan and Park 2020 [77] Cross-sectional	Chinese and Korean international college students in the U.S. (n=266)	1) Multigroup Ethnic Identity Measure (MEIM): 12-item questionnaire adapted from the full MEIM assessing a sense of membership and feelings toward ethnicity and ethnic identity 2) American Identity Measure: 12-item questionnaire adapted from the full MEIM assessing sense of membership and feelings toward the U.S.	1) Sleep quality: PSQI, 19-item questionnaire designed to measure self-reported sleep quality during the previous month	↓ Compared to marginal orientation, bicultural (aOR=0.44, β=−0.81, SE=0.38) and Asian orientation (aOR=0.40, β=−0.91, SE=0.39) were associated with better sleep quality in models that adjusted for sex, school year, SES, and country of birth → No association between American orientation and sleep quality
Gonzalez and Lu 2018 [63] Cross-sectional	Chinese breast cancer survivors throughout the U.S. (n=80)	1) Stephenson Multigroup Acculturation Scale (SMAS): 32-item questionnaire to measure ethnic society immersion and dominant society immersion	1) Sleep quality: Chinese version of the PSQI, a 19-item questionnaire designed to measure self-reported sleep quality during the previous month	→ Mean acculturation score for participants with a total PSQI score <5 was not meaningfully different than the mean acculturation score for participants with a PSQI score ≥5
Martinez-Miller et al. 2018 [43] Cross-sectional	Hispanic/Latino adults in the Sacramento Valley region of California as part of the Sacramento Area Latino Study on Aging (SALSA) and the Niños Lifestyle and Diabetes Study (NLDS) (n=2,386)	1) ARSMA-II: measure of language use and ethnic identity and interaction comprised of a 17-item questionnaire on Mexican cultural orientation and a 13-item questionnaire on Anglo cultural orientation	1) Sleep class: latent class of overall sleep comprised of self-reported restless sleep, general fatigue, waking up far too early, trouble falling asleep, and waking up several times a night 2) Restless sleep: self-reported restless sleep extracted from the Center for Epidemiological Studies Depression Scale 3) Sleep duration (sub-sample only): self-reported average hours of sleep, computed as the weighted average of weekday and weekend sleep 4) Sleep apnea (sub-sample only): self-reported medical diagnosis of sleep apnea	↑ First-generation older Latinos with high US acculturation, vs. high acculturation towards another origin/ancestral country, had less restless sleep (PR=0.67, 95% CI: 0.54-0.84) and a higher likelihood of being in the best sleep class than the worst (OR=1.62, 95% CI: 1.09-2.40) ↓ Second-generation participants with stable-high intergenerational U.S. acculturation had a higher prevalence of short sleep duration than participants with low intergenerational acculturation (PR=2.86, 95% CI: 1.02-7.99)
Im et al. 2017 [50] Cross-sectional	Multi-ethnic midlife women (40 to 60 years old) throughout the U.S. (n=1,054)	1) Suinn-Lew Asian Self-Identity Acculturation Scale (SL-ASIA): 21-item measure based on the ARSMA used to assess acculturation in Asian populations by assessing preferences for food, music, customs, language, and close friends	1) Sleep symptoms: using the Sleep Index for Midlife Women, a measure of sleep-related symptoms, such as sleep disorders, chronic pain, mood disorders, and vasomotor symptoms	→ In models that controlled for sociodemographic characteristics and menopausal status, only self-reported racial/ethnic identity (rather than immigration status, the level of acculturation, or the length of stay in the U.S.) was associated with sleep-related symptoms ↓ For race/ethnicity stratified models, Hispanic women who were immigrants, stayed longer in the U.S., and were more acculturated tended to report more sleep-related symptoms and a higher total severity → Immigration variables were not related to sleep-related symptoms in other race/ethnicity groups
Zeiders et al. 2017 [38] Longitudinal	Mexican and Mexican American young adults in Southwest U.S. (n=246)	1) ARSMA-II: established measure of language use and ethnic identity and interaction comprised of a 17-item questionnaire on Mexican cultural orientation and a 13-item questionnaire on Anglo cultural orientation	1) Sleep duration: using the 7-day phone protocol, the self-reported mean time in between reported bedtime and wake time across seven calls 2) Sleep variability: using standard regression, how much each individual varied from their own overall average sleep duration sleep	→ Bicultural (high Anglo-high Mexican) and enculturated orientation (low Anglo-high Mexican) reported no association between discrimination and sleep duration ↓ Acculturated orientation (high Anglo-low Mexican) reported a negative association between discrimination and sleep duration and marginalized orientation (low Anglo-low Mexican) reported a positive association
D’anna-Hernandez et al. 2016 [39] Longitudinal	Pregnant Mexican American adult women in an urban U.S. city (n=60)	1) SASH: 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations	1) Sleep duration: reported bed and wake times and total hours of sleep via a sleep diaries on three consecutive days at each phase 2) Sleep onset: minutes to fall asleep via sleep diary 3) Sleep disruptions: times woke during the night via sleep diary 4) Feeling refreshed upon waking: rated 1 (extremely tired) to 7 (extremely refreshed) in sleep diary	↓ In cross-sectional analyses, maternal acculturation was only associated with feeling refreshed upon waking (β=−0.36, SE=0.16) ↓ In longitudinal analyses, multilevel modeling revealed that women who were more acculturated reported more times up during the night and lower feelings of being refreshed upon awakening across pregnancy
Nuyen et al. 2016 [78] Cross-sectional	Hispanic/Latino adults in southern California (n=573)	1) Brief Acculturation Scale for Hispanics (BASH): a four-item language-based questionnaire adapted from the Short Acculturation Scale for Hispanics	1) Daytime sleepiness: ESS, an 8-item questionnaire that asks respondents to rate their likelihood of falling asleep in eight different contexts	→ Acculturation did not moderate the relationship between EDS and depression
Hale et al. 2014 [46] Cross-sectional	Multi-ethnic adult women in Oakland, CA, Los Angeles, CA, and Newark, NJ as part of SWAN (n=1,180)	1) SASH: 4-item adaption of the 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations, extended to other languages (Japanese, Chinese)	1) Sleep complaints: Four questions about sleep complaints in the past two weeks (difficulty falling asleep, awakenings, difficulty returning to sleep, and typical sleep quality) adapted from the Women’s Health Initiative Insomnia Rating Scale (WHIIRS)	↓ Language acculturation or unmeasured factors associated with language acculturation mediated 40.4% (95% CI: 28.5%-69.8%) of the association between immigrant status and any sleep complaint
Sawanyawisuth et al. 2013 [49] Cross-sectional	Hispanic adults of Mexican descent and non-Hispanic White adults in San Diego County, CA as part of The Sleep Health and Knowledge in U.S. Hispanics Project (n=3,667)	1) SASH: 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations	1) Restless leg syndrome (RLS): diagnosed using patient-reported answers to the four essential criteria by the International Restless Legs Study Group	↓ Hispanic adults of Mexican descent with high acculturation had significantly higher RLS prevalence than those with low acculturation (17.4% vs. 12.8%, respectively)
Kachikis and Breitkopf 2012 [19] Cross-sectional	Hispanic/Latina, White/non-Hispanic, and Black/non-Hispanic adult women in southeast Texas (n=2,670)	1) SASH: 5-item adaption of the 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations	1) Sleep duration: self-reported average number of hours of sleep each night in the past month 2) Sleep quality: self-reported rating of overall quality of sleep on 5-point Likert scale 3) Sleep adequacy: self-reported frequency of feeling like one got the amount of sleep needed in the past month	→ No association between acculturation and sleep duration in models adjusted for sociodemographic characteristics, depression, anxiety, and perceived stress ↓ Higher acculturation was associated with poorer sleep quality in models adjusted for sociodemographic characteristics, depression, anxiety, and perceived stress (β=−0.06, SE=0.02) → No association between acculturation and sleep duration among the Hispanic sample (n=1,966) in models adjusted for sociodemographic characteristics, depression, anxiety, and perceived stress
Green et al. 2010 [44] Cross-sectional	Hispanic/Latino women in Newark, NJ as part of SWAN (n=419)	1) SASH: 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations	1) Sleep problems: Four questions assessing problems with sleep initiation, maintenance, early awakening, and overall quality in the past two weeks	→ No difference in the median sleep problem score between the low acculturation group (3.0, IQR: 0.0-6.0) and the high acculturation group (3.0, IQR: 0.0-5.0)
Cantero et al. 1999 [41] Cross-sectional	Hispanic/Latino women in Los Angeles, CA as part of the Proyecto a Su Salud study (n=573)	1) Cantero 1999 Measure: Created acculturation scale, adapted from ARSMA, that included an 11-item measure of language acculturation and length of residence in the U.S.	1) Sleep duration: self-reported average hours of sleep per night	→ No difference in the prevalence of short sleep duration between the low (53.4%), medium (54.5%), and high (53.4%) acculturation groups
2. Acculturative Stress Questionnaires
Lee et al. 2021 [52] Cross-sectional	Chinese and Korean Americans in the Washington, DC. Metropolitan Area (n=400)	1) HSI: 9-item occupational and emotional stress subscale of the HSI for use among Asian populations	1) Sleep disturbance: 8-item questionnaire from PROMIS to measure self-reported perceptions of sleep quality, depth, and restoration within the past seven days 2) Sleep duration: self-reported continuous value of sleep duration calculated from usual sleep and wake time in hours and minutes	↓ Greater acculturative stress was associated with a higher prevalence of sleep disturbance in Poisson models that adjusted for sociodemographic characteristics and chronic conditions (aPR=1.18, 95% CI: 1.06-1.31). Effect measure modification tests suggested that this association was only significant for women (aPR=1.30; 95% CI: 1.13-1.49) and those who identity as “very Asian” (aPR=1.21; 95% CI: 1.08-1.35) ↓ One-unit increase in acculturative stress was associated with 0.08 hr less sleep in linear models that adjusted for sociodemographic characteristics and chronic conditions (β=−0.08, SE=0.04)
Green et al. 2021 [17] Cross-sectional	First-generation Hispanic/Latinx immigrants in central Virginia (n=231)	1) Riverside Acculturation Stress Inventory (RASI): discrimination subscale of the RASI used to capture acculturative stress due to racial/ethnic discrimination	1) Sleep duration: self-reported average hours of sleep per night in a regular week 2) Difficulty falling asleep: self-reported rating of difficulty falling asleep during a regular week 3) Waking at night: self-reported number of awakenings falling asleep during a regular week 4) Difficulty going back to sleep: self-reported rating of difficulty going back to sleep during a regular week 5) Sleep quality: self-reported rating of general sleep quality based on a single survey question	↓ Nocturnal awakenings, fatigue, and self-reported sleep quality mediated approximately 13% of the total effect of perceived discrimination on self-reported physical health
Park et al. 2020 [51] Cross-sectional	Korean American adults throughout the U.S. (n=343)	1) Acculturative Stress Index: 17-item questionnaire with 6 subscales (homesickness, social isolation, employment barrier, discrimination, civic disengagement, and family problems) to evaluate acculturative stress	1) Sleep duration: self-reported average hours of sleep per night in the past month, computed as the weighted average of weekday and weekend sleep	↓ In women, higher homesickness (β = −23.19) and lower civic disengagement (β = 17.75) were associated with shorter sleep duration in models that adjusted for sociodemographic characteristics, comorbidities, sleep environment, and acculturation ↓ In men, higher isolation was associated with shorter sleep duration (β = −13.73)
Alcántara et al. 2019 [39] Cross-sectional	Hispanic/Latino adults in four major metropolitan areas (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA) as part of HCHS/SOL (n=1,192)	1) HSI: abbreviated 17-item questionnaire that measures distress/worry associated with interpersonal, economic, and immigration conflict accompanying the process of adaptation and integration into a new nonnative culture within the past three months	1) Insomnia: ISI, a 7-item instrument which assesses the nature, severity, and impact of insomnia 2) Sleep duration: actigraphy-measured average duration of time scored as sleep between sleep onset and sleep offset across all days 3) Sleep efficiency: actigraphy-measured sleep duration divided by time between sleep onset and sleep offset averaged across all main sleep intervals 4) Sleep variability: SD of sleep duration across all days	↓ Greater acculturation stress was associated with greater insomnia symptoms, after adjusting for sociodemographic characteristics, health behaviors and conditions, and other stressors (ß=0.75, SE=0.26) → No consistent associations between acculturative stress and actigraphic sleep measures
Alcántara et al. 2017 [14] Cross-sectional	Hispanic/Latino adults in four major metropolitan areas (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA) as part of HCHS/SOL (n=5,313)	1) HSI: abbreviated 17-item questionnaire that measures distress/worry associated with interpersonal, economic, and immigration conflict accompanying the process of adaptation and integration into a new nonnative culture within the past three months	1) Insomnia: Women’s Health Initiative Insomnia Rating Scale (WHIIRS) a 5-item questionnaire that asks respondents to rate how frequently they experience difficulty with sleep initiation and maintenance over the past four weeks 2) Daytime sleepiness: ESS, an 8-item questionnaire that asks respondents to rate their likelihood of falling asleep in eight different contexts 3) Sleep duration: calculated from self-reported average weekday bedtime and wake time	↓ Greater acculturation stress was associated with greater insomnia symptoms, after adjusting for sociodemographic characteristics, health behaviors and conditions, and other stressors (exp(b) = 1.06, 95% CI: 1.03-1.10) ↓ Greater acculturative stress was associated with greater daytime sleepiness, after adjusting for sociodemographic characteristics, health behaviors and conditions, and other stressors (exp(b) = 1.06, 95% CI: 1.02-1.10) → No association between acculturative stress and sleep duration
Suh et al. 2013 [54] Cross-sectional	Korean American adult women in Southeast U.S. (n=30)	1) Revised Social, Attitudinal, Familial, and Environmental Acculturative Stress Scale (R-SAFE): 25-item questionnaire to evaluate acculturative stress in multiple contexts	1) Sleep quality: PSQI, 19-item questionnaire designed to measure self-reported sleep quality during the previous month	↓ Higher acculturative stress was associated with worse daytime dysfunction, but was not associated with global sleep quality
Ehlers et al. 2010 [53] Cross-sectional	Mexican American young adults in San Diego County, CA (n=294)	1) Caetano Acculturation Stress Scale: 11-item questionnaire to evaluate acculturative stress	1) Sleep quality: PSQI, 19-item questionnaire designed to measure self-reported sleep quality during the previous month	↓ Acculturative stress was associated with poorer global sleep quality
3. Proxy Measures of Acculturation
García et al. 2020 [20] Cross-sectional	Nationally representative sample of U.S.-born non-Latino white adults vs. U.S.-born and non-U.S.-born Latino adults in NHIS 2004-2017 (n=303,204)	1) Citizenship: self-reported citizenship status 2) Length of residence in U.S.: self-reported years lived in the U.S. 3) Language: language of interview	1) Sleep duration: self-reported average hours of sleep in a 24-hour period	↑ Non-U.S.-born Puerto Ricans, Dominicans, Cubans, and Central/South Americans, and “Other” Latinos had greater odds of short sleep duration than their U.S.-born counterparts ↓ Non-U.S.-born Mexicans had lesser odds of short sleep duration than their U.S.-born counterparts
Gaston et al. 2020 [57] Cross-sectional	Nationally representative sample of U.S.-born non-Hispanic white adults vs. U.S.-born and non-U.S.-born Mexican, Puerto Rican, Cuban, Dominican, and Central/South American adults in NHIS 2004-2017 (n= 283,767)	1) Language: language of interview	1) Sleep duration: self-reported average hours of sleep in a 24-hour period 2) Sleep quality: self-reported number of nights with trouble falling asleep, trouble staying asleep, frequent sleep medication use, and waking up feeling rested in the week before the interview	↓ Overall, only Puerto Rican homeowners were more likely than NH-Whites to report <6 hours and 6-<7 hours of sleep duration; sensitivity analyses suggest that associations between housing tenure status and sleep vary by language acculturation and heritage group. Puerto Rican participants with high acculturation (English language of interview) had slightly worse sleep duration and quality than Puerto Rican participants with low acculturation (Spanish language of interview)
Murillo et al. 2019 [12] Cross-sectional	Nationally representative sample of Latino adults of Mexican/Mexican American, Puerto Rican, Dominican, Central or South American, and Cuban/Cuban American origin in NHIS 2013-2015 (n=13,537)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth 2) Length of residence in U.S.: self-reported years lived in the U.S.	1) Sleep duration: self-reported average hours of sleep in a 24-hour period	↓ Compared to U.S.-born participants, non-U.S.-born participants living in the U.S. for any amount of time were less likely to have a short sleep duration in models that adjusted for age, sex, education, marital status, employment status, and Latino subgroup ↓ Non-U.S. born participants who lived in the U.S. for <10 years were more likely to have a normal sleep duration than those who lived in the U.S. for ≥10 years Those who lived in neighborhoods with medium and high social cohesion (vs. low) were significantly more likely to report normal sleep duration and these associations differed by Latino subgroup
Patel et al. 2015 [58] Cross-sectional	Hispanic/Latino adults in four major metropolitan areas (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA) as part of HCHS/SOL (n=11,860)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth 2) Length of residence in U.S.: self-reported years lived in the U.S.	1) Sleep duration: self-reported average hours of sleep, computed as the weighted average of weekday and weekend sleep (difference between habitual wake time and bedtime)	↓ Compared to U.S.-born Hispanic/Latinos, non-U.S.-born Hispanic/Latinos who lived in the U.S. for ≥10 years had decreased odds of both short sleep (aOR=0.84, 95% CI: 0.68, 1.03) and long sleep (aOR=0.78, 95% CI: 0.62, 0.99) in models that adjusted for demographic and socioeconomic variables ↓ Odds of both short sleep and long sleep were slightly higher in non-U.S.-born Hispanic/Latinos who have lived in the U.S. for 10 or more years, vs. <10 years
Jackson et al. 2014 [79] Cross-sectional	Nationally representative sample of U.S.-born and non-U.S.-born non-Hispanic Asian and non-Hispanic white adults in NHIS 2004-2011 (n=125,610)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth	1) Sleep duration: self-reported average hours of sleep in a 24-hour period	↓ Most Asian participants were non-U.S.-born (74%), and U.S.-born participants had shorter sleep duration than non-U.S.-born participants; the Asian-White disparity was largest in certain sectors (e.g., finance/information, healthcare)
Whinnery et al. 2014 [55] Cross-sectional	Nationally representative sample of adults in NHANES 2007-2008 (n=4,850)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth 2) Language: self-reported primary language spoken at home	1) Sleep duration: self-reported usual hours of sleep on weekdays or work nights	↓ Mexico-born participants reported less short sleep than U.S.-born participants (aOR=0.63, 95% CI: 0.41, 0.90) ↓ Spanish-only speakers reported less very short sleep
Manber et al. 2013 [62] Cross-sectional	Pregnant Hispanic/Latino adult women receiving perinatal services in 10 community obstetric/gynecologi c clinics serving the greater San Diego, California area (n=1,289)	1) Language: language of interview	1) Insomnia: ISI, a 7-item instrument which assesses the nature, severity, and impact of insomnia	↓ Completing the interview in English was a predictor of clinically significant insomnia (OR=2.61, 95% CI: 1.80, 3.79)
Young et al. 2013 [25] Cross-sectional	Hmong adults in Wisconsin (n=747)	1) Length of residence in U.S.: self-reported years lived in the U.S. 2) Diet: self-reported Hmong or Western diet 3) Religion: self-reported religious practices (Shamanism, Christianity, or other)	1) Sleep problems: self-reported occurrence and frequency of sleep apnea (snoring, breathing pauses), REM-related disorders (sleep paralysis at sleep onset, waking, and mid-sleep), hypnogogic hallucinations, nightmares, cataplexy, insomnia, and excessive daytime sleepiness (EDS) 2) Sleep apnea (sub-sample only): in-home portable polysomnography to measure apnea-hypopnea index (AHI) for a sub-sample of participants (n=37)	↓ Participants who lived in the U.S. for >10 years had higher odds of snoring than those who lived in the U.S. <10 years ↓ Participants who lived in the U.S. for >10 years had higher odds of nightmares than those who lived in the U.S. for <10 years ↑ Participants who practiced Shamanism had higher odds of hypnogogic hallucinations than those who practiced Christianity or other religions → No other associations between diet and religion and sleep problems
Heilemann et al. 2012 [60] Cross-sectional	Hispanic/Latino adult women in an urban Northern California community (n=312)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth 2) Language: self-reported preferred language 3) Early U.S. socialization: immigration to the U.S. before 18 years of age	1) Sleep disturbance: General Sleep Disturbance (GSDS), a 21-item instrument for sleep disturbance in the past seven days	→ Sleep disturbance did not differ by country of birth ↓ Participants who preferred English reported more sleep disturbances than women who preferred Spanish
Hale et al. 2011 [28] Cross-sectional	Nationally representative sample of U.S.-born vs. non-U.S.-born Mexican adults in NHIS 1990 (n=1,436)	1) U.S.-born vs. non-U.S.-born: self-reported place of birth	1) Sleep duration: self-reported average hours of sleep in a 24-hour period	↓ U.S.-born Mexican Americans are more likely to be short sleepers than non-U.S.-born Mexican immigrants in models that adjusted for demographic, socioeconomic, and health behavior variables, including stress, smoking, and BMI (aOR=1.25)
Seicean et al. 2011 [18] Cross-sectional	Nationally representative sample of U.S.-born Mexican adults vs. non-U.S.-born Mexican adults in NHANES 2005-2006 (n=1,042)	1) U.S.-born vs. Mexico-born: self-reported place of birth 2) Language: self-reported language spoken at home	1) Short habitual sleep time (SHST): self-reported usual hours of sleep on weekdays or work nights 2) Insomnia: self-reported insomnia as defined by the NHLBI working definition 3) Sleep quality: self-re- ported perception of insufficient sleep during the past month or “trouble sleeping” ever reported to a physician or other health professional	↓ Mexico-born immigrant status was associated with lower odds of SHST (aOR=0.7, 95% CI: 0.6-0.9), insomnia (aOR=0.3, 95% CI: 0.2-0.5), and sleep-associated functional impairments (aOR=0.4, 95% CI: 0.2-0.8) ↓ Overall, there was a lower prevalence of poor sleep and poor sleep-related outcomes in Mexico-born immigrants vs. general U.S. population and to U.S.-born Mexican Americans ↓ Among Mexican American men, increased levels of English (vs. Spanish) spoken at home associated with increased risk of poor sleep
Seicean and Seicean 2010 [61] Cross-sectional	Nationally representative sample of Mexican-born vs. other Latino-born adults in NHANES 2005-2006, 2007-2008 (n=1,806)	1) Mexico-born vs. non-Mexico-born: self-reported place of birth 2) Proportion lifetime in immigration (PLI): calculated by dividing self-reported years lived in the U.S. by participant age 3) Language: self-reported language spoken at home	1) Insomnia: self-reported insomnia as defined by the NHLBI working definition	↓ Mexico-born ethnicity had a protective effect against severe insomnia (aOR=0.4, 95% CI: 0.2, 0.7) after adjusting for sociodemographic characteristics, health behaviors and conditions, and immigration-related characteristics ↓ Among Mexico-born immigrants, a greater PLI was associated with higher adjusted odds of severe insomnia → No association between English-use at home and severe insomnia
Chakraborty et al. 2003 [56] Cross-sectional	Mexican American adult women from Starr County, TX as part of the Unidos en Salud: Weight Loss for Mexican Americans study (n=390)	1) Migration History Score (MHS): 9-item questionnaire to measure migration history, including birthplace of participant, birthplace of participant’s parents and grandparents, and length of residence in the U.S.	1) Sleep duration: number of hours spent sleeping per night over the past week, measured with the 7-day Physical Activity Recall	→ Migration history score was not associated with sleep duration (logit α SE= −0.197 α .146)
4. Multiple acculturation measures (i.e., acculturation scale and proxy measure)
Ryu et al. 2021 [59] Cross-sectional	Nationally representative sample of non-Hispanic Asian/Native Hawaiian/Other Pacific Islander adults in the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) 2012-2013 (n=1,401)	1) Bidimensional Acculturation Scale (BAS): two sets (English and Asian language) of 12-item questionnaires measuring frequency of language use, electronic media consumption, and linguistic proficiency 2) U.S.-born vs. non-U.S.-born and length of residence in U.S.: additionally included proxy variables of acculturation, self-reported place of birth and years lived in the U.S.	1) Sleep duration: self-reported average number of hours of sleep on a typical day in the past month 2) Sleep difficulties: self-reported trouble falling asleep or staying asleep in the past twelve months	↑ Sleep duration longer than recommended among Bicultural and Asian orientation groups, vs. non-Asian orientation group, in models that adjusted for sociodemographic characteristics, comorbidities, and health behaviors; sensitivity analyses showed this is is driven by long sleep in Bicultural group ↑ Non-U.S.-born Asian participants living in U.S. for 6-20 years and for ≥21 years reported 0.17 and 0.28 hours per day shorter sleep duration, respectively, vs. U.S.-born Asian participants in models that adjusted for sociodemographic characteristics, comorbidities, health behaviors, acculturation → No association for non-U.S.-born Asian participants who lived in the U.S. for ≤5 years → After adjusting for sociodemographic characteristics, comorbidities, and health behaviors, there was no association between the BAS acculturation measure and sleep difficulties ↓ Non-U.S.-born Asian participants who lived in the U.S. for ≤5 years had lower odds for trouble falling asleep than U.S.-born individuals in models that adjusted for sociodemographic characteristics, comorbidities, health behaviors, and acculturation, and the protective association attenuated with longer years lived in the U.S.
Shen and Gellis 2021 [15] Cross-sectional	College students at a private university in northeastern U.S., including English as a Second Language (ESL) students (n=352)	1) SASH: adapted English language questions only from the 12-item questionnaire measuring language use, media preference, and ethnic and social relations in Hispanic populations 2) Language: self-reported native English language status	1) Insomnia: ISI, a 7-item instrument which assesses the nature, severity, and impact of insomnia	→ No significant association between language acculturation measured via SASH and insomnia severity ↑ ESL students reported higher levels of insomnia severity than English-only native students and were more likely to meet criteria for insomnia (OR = 2.88) after adjusting for race, gender, non-sleep depression, anxiety

^aStudies are ordered chronologically by publication date within each acculturation measurement subheading

^bThe direction of the arrow refers to evidence of positive or negative acculturation: ↑ indicates positive acculturation, or that U.S. acculturation is beneficial to the sleep outcome; ↓ indicates negative acculturation, or that U.S. acculturation is harmful to the sleep outcome; → indicates no association between U.S. acculturation and the sleep outcome.

Abbreviations: ARSMA-II=Acculturation Scale for Mexican-Americans-II; ESS=Epworth Sleepiness Scale; HCHS/SOL=Hispanic Community Health Study/ Study of Latinos; HSI=Hispanic Stress Inventory; ISS=Insomnia Severity Index; NHANES=National Health and Nutrition Examination Survey; NHIS=National Health Interview Survey; NHLBI=National Heart, Lung, and Blood Institute; PROMIS=Patient-Reported Outcomes Measurement System; PSQI=Pittsburgh Sleep Quality Index; SAS-K=Short Acculturation Scale for Koreans; SASH=Short Acculturation Scale for Hispanics; SWAN=Study of Women’s Health Across the Nation