Substance Use and Treatment Disparities Among Asian Americans, Native Hawaiians, and Pacific Islanders: A Systematic Review

Abstract

Background:

The increasing relevance of substance use disorder (SUD) within the Asian American, Native Hawaiian, and Pacific Islander (AA&NH/PI) communities, particularly amidst rising anti-Asian hate incidents and the disproportionate health and economic challenges faced by the NH/PI community during the COVID-19 pandemic, underscores the urgency of understanding substance use patterns, treatment disparities, and outcomes.

Methods:

Following PRISMA guidelines, 37 out of 231 studies met the search criteria. Study characteristics, study datasets, substance use rates, SUD rates, treatment disparities, treatment quality, completion rates, and analyses disaggregated by the most specific AA&NH/PI ethnic group reported were examined.

Results:

Despite increased treatment admissions over the past two decades, AA&NH/PI remain underrepresented in treatment facilities and underutilize SUD care services. Treatment quality and completion rates are also lower among AA&NH/PI. Analyses that did not disaggregate AA and NHPI as distinct groups from each other or that presented aggregate data only within AA or NHPI as a whole were common, but available disaggregated analyses reveal variations in substance use and treatment disparities among ethnic groups. There is also a lack of research in exploring within-group disparities, including specific case of older adults and substance use.

Conclusion:

To address disparities in access to substance use treatment and improve outcomes for AA&NH/PI populations, targeted interventions and strategic data collection methods that capture diverse ethnic groups and languages are crucial. Acknowledging data bias and expanding data collection to encompass multiple languages are essential for fostering a more inclusive approach to addressing SUD among AA&NH/PI populations.

1. Introduction

Substance use is a critical public health concern, exerting a significant impact on physical, mental, and socioeconomic characteristics (Lo and Cheng, 2011). Addressing substance use requires a comprehensive approach that includes prevention, early intervention, treatment, and support services to mitigate its burden on individuals and society (Substance et al., 2016). While Asian Americans are the fastest growing racial/ethnic group in the United States, and are projected to surpass Hispanics as the largest immigrant group by 2055 (Budiman, 2021), Asian American individuals with substance use disorder (SUD) have been understudied. Similarly, despite the growth in the Native Hawaiian and Pacific Islander population over the past decade (U.S. Census Bureau, 2021), there is also a lack of research on NH/PI individuals with SUD. The diverse and sizable Asian American, and Native Hawaiian, and Pacific Islander (AA&NH/PI) populations, comprising approximately 20.6 million Asians and 690,000 Native Hawaiians or other Pacific Islanders (Monte and Shin, 2022), demands increased attention to substance use and SUD, particularly in the wake of rising Asian-hate crimes and the disproportionate toll the COVID-19 pandemic had on the health and economic well-being of the NH/PI community. These incidents have not only underscored the need to address SUD but have also highlighted the significant impact on mental health in the AA&NH/PI communities (Chen et al., 2020; Huynh et al., 2023; Kaholokula et al., 2022; Lee and Waters, 2021; Shimkhada and Ponce, 2022; Wu et al., 2021), requiring a deeper understanding of substance use patterns, disparities in treatment access, and outcomes.

The model minority stereotype perpetuates the image of Asian Americans as a population with great academic, economic, and social success as a result of merit (Kiang et al., 2016). The model minority myth reinforces an image of healthiness on a broad cultural scale, which downplays health problems Asian Americans may face, including SUD. Consequently, this stereotype obscures the significant variability within the Asian American population, including distinct ethnic groups (Wu et al., 2016; Yu et al., 2014).

Furthermore, Asian Americans, Native Hawaiians, and Pacific Islanders are often aggregated into a single group that undermines the heterogeneity of specific ethnicities. This homogenization impedes understanding of the diverse experiences and needs of different AA&NH/PI ethnic groups, regarding SUDs. Small sample sizes of specific subgroups contribute to the difficulty in studying and comprehending their unique substance-related challenges (Shimkhada et al., 2021). The lack of disaggregation hampers the development of targeted interventions and interventions tailored to the cultural values and preferences of different Asian American ethnic groups (Hoeffel, 2012). In addition, it is important to recognize that different ethnic groups can also diverge in experiences that go beyond culture, such as disparities related to colorism, distinct refugee backgrounds, and varying trauma experiences (Chen et al., 2020; Okazaki et al., 2022; Sue et al., 2012). The lack of Asian ethnic group disaggregation means that SUD are not contextualized to specific populations, resulting in an incomplete understanding of the diverse substance-related needs and interventions for the different ethnic groups of Asian Americans. In a similar vein, the NHPI community often gets aggregated with Asian American communities despite the requirement for separate categorization by the Office of Management and Budget (Office of Management Budget., 1997), reflecting longstanding research gaps in NHPI health. Consequently, specific substance use needs within AA&NH/PI populations are often overlooked and understudied due to their categorization as “other race” in research. Although this classification aims to streamline data collection or in other cases deemed statistically necessary due to small sample sizes, it results in insufficient attention to the SUDs specific to Asian Americans and NHPIs. By combining AA&NH/PI into a heterogeneous category that includes various races and ethnicities, this population is effectively overshadowed, contributing to AA&NH/PI underrepresentation in research and gaps of knowledge surrounding AA&NH/PI substance use. The impetus to fix poor data quality is hampered by the model minority stereotype in a reinforcing cycle (Yi et al., 2022). Addressing the underrepresentation of AA&NH/PI in research is crucial because currently, public health practitioners, researchers, and health advocates have base from which to develop solutions. Consequently, AA&NH/PI do not receive adequate attention regarding their unique substance use challenges and needs.

In our systematic review, we aim to build upon existing literature (Fong, T. and Tsuang, J., 2007; Wang et al., 2023) by providing a comprehensive analysis of substance use and SUD among Asian American and NHPI patients with a specific focus on various ethnic groups within the AA&NH/PI population, while paying attention to data constraints. Our review seeks to contribute in several ways: offering a more detailed and up-to-date analysis of SUD among AA&NH/PI populations with a focus on disaggregated data for ethnic groups, data limitations, and recent developments. Specifically, this review aims to: (1) Identify and synthesize results of studies that have examined the prevalence of SUD among AA&NH/PI; (2) Explore the barriers and facilitators to accessing substance use treatment services among AA&NH/PI; (3) Examine the effectiveness of existing substance use treatment interventions targeting the AA&NH/PI population; (4) Evaluate studies that disaggregate by AA&NH/PI ethnic groups; and (5) Identify research gaps and provide recommendations for future studies.

2. Methods

The search strategy aimed to identify relevant studies on substance use treatment services and interventions for AA&NH/PI populations. The following electronic databases were searched due to their extensive coverage of health-related literature: PubMed, CINAHL, and Web of Science. The search included articles published from 1985 to November 2023, encompassing a substantial time frame to capture a wide range of relevant literature. Various search terms and combinations, encompassing Asian American ethnic groups (i.e., Chinese Americans, Korean Americans, and etc), terms representing individuals of Asian heritage (i.e., Asian Pacific Islander), substance use disorder, and addiction treatment services were used (Appendix A). A snowball sampling technique was employed by reviewing the reference lists of collected papers to identify additional relevant studies. Inclusion criteria for article selection included studies published in English that reported on AA&NH/PI undergoing substance use treatment services and/or substance use interventions. Exclusions comprised studies that did not distinguish Asian Americans from other race-ethnicity groups, studies not focused on substance misuse/SUD, conference abstracts/posters, other systematic reviews and/or meta-analyses, study protocols without results, and studies focused solely on tobacco use were excluded. Duplicate records were removed, and a full-text review was conducted for the remaining articles. Exclusion reasons were recorded, and relevant information was extracted from the articles. The process of article screening and selection is illustrated in Appendix B. The protocol was registered on PROSPERO (#CRD42022363019). In cases where there were discrepancies in study inclusion, four authors reviewed the articles and engaged in discussions to reach a consensus. A standardized data extraction form was used to capture relevant information from the selected studies. The following data were extracted from each study: author(s), publication year, study design, sample characteristics (e.g., sample size, demographics), substance use measures, treatment approaches, and findings related to disparities.

The extracted data were analyzed thematically to identify common themes and patterns across the studies (Mihas, 2023). Findings were summarized and presented in the results section, highlighting the key findings related to study characteristics involving AA&NH/PI research on substance use treatment and characteristics of studies that included specific ethnic group data. The extracted articles’ results and discussion sections were organized by topic, with separate findings reported for AA, NH/PI, and specific AA&NH/PI ethnic groups where possible (PONCE et al., 2023).

3. Results

3.1. Study Selection

A total of 530 articles were identified, of which 289 were duplicates and subsequently removed. Among the 241 unique articles, 165 were identified as irrelevant and excluded during the title and abstract screening phase. As a result, 76 articles were eligible for full-text screening. We then removed 39 articles in the full-text screening stage primarily due to a lack of focus on substance misuse and substance use disorders (n=14), the absence of mention of substance use treatment services (n=7), sole focus on tobacco use (n=5), no reference to Asian American or NHPI populations (n=1), and indistinguishability between AA&NH/PI and other race and ethnic groups (n=5). One study was based outside of the United States and six studies were not empirical papers. In total, 37 studies were included in the study. Of the 37 studies, 11 presented results by further disaggregating into Asian or NH/PI ethnic groups, while another 9 aggregated Asian American and NH/PI groups together.

3.2. Characteristics of the Included Studies

The characteristics of the included studies are presented in Table 1. Most of the included studies employed quantitative methods (71.1%, n=27), followed by mixed-methods (15.8%, n=6), and qualitative methods (10.5%, n=4). The datasets used in these studies were diverse, encompassing primary data collection through interviews, data from treatment case files, case study data from clinics, survey data, and data from federally funded studies of patients admitted to community-based drug treatment in various states. Among the included studies, the largest proportion utilized national, population-level datasets (43.2%, n=16), followed by community and locally-based datasets (35.1%, n=13), and state-level data (21.6%, n=8). Among studies that utilized national, population-level datasets, common datasets included the National Survey on Drug Use and Health (NSDUH) (50.0%, n=8) and Treatment Episode Data Set (TEDS) (31.3%, n=5). Common datasets among state-level datasets were New York state’s Client Data System (CDS) and the California Treatment Outcome Project (CalTOP).

Table 1.

Study characteristics

First Author (Year)	Year (s) of study	Study Type	Study population/Participants	Asian ethnic groups identified	Dataset/Method for collecting data	If a survey is administered, language (s) used for administration	Main findings
Alegría et al. (2022) (Alegría et al., 2022)	2015–2017	Quantitative	White, Black, Asian Am, Native American, Puerto Rican/Hispanic, Other, Unknown	No	New York State Department of Health (NYSDOH) supplied data	N/A	1) Asian Am enrollees receive significantly less psychosocial treatment than 2) Whites Asian Am are treated more favorably by providers than Whites 3) Asian Am continue treatment less frequently than Whites and other racial/ethnic groups 4) Asian Am face barriers in substance use treatment engagement and follow-up after withdrawal 5) Place of residence may contribute to treatment disparities for Asian Am due to limited access in some neighborhoods
Nguyen et al. (2022)(Nguyen et al., 2022)	2011–2021	Quantitative	AA&NH/PI	No	HHS surveys and data systems, including those developed by the National Center for Health Statistics and CMS, along with previous work examining disaggregated AA&NH/P I data collection.		1) Surveys collecting AA&NH/PI data increased from 2011 to 2021 2) Some groups still need additional disaggregation in data collection standards, such as Pakistani, Sri Lankan, Burmese, and Nepalese people.
Subica et al. (2022) (Subica et al., 2022)	2021	Quantitative	NH/PI	No	Online and paper-and-pencil-surveys	N/A but interviews were offered for participants with limited English proficiency	1) Over one in four NH/PI adults in the total sample screened positive for alcohol use disorder. 2) Over one-third of NH/PIs reported lifetime illicit substance use. 3) One-third of NH/PI participants reported needing past-year behavioral health treatment, with unmarried individuals and those experiencing COVID-19 distress more likely to report treatment need. 4) Despite reported treatment needs, 60% of participants avoided or delayed seeking treatment.
Von Gunten et al. (2021)(Von Gunten and Wu, 2021)	2015–2017	Quantitative	Asian Am, White non-Hispanic, Black non-Hispanic, Hispanic, Other (Native American, Alaskan Native, NH, PI)	No	NSDUH	English, Spanish	1) Asian Am individuals had the lowest treatment prevalence of 3% in the study.
Sahker et al. (2021)(Sahker et al., 2021)	2006–2017	Quantitative	AA&NH/PI	No	Treatment Episodes Dataset (TEDS)	N/A	1) Asian Am completion rates higher than non-Asian Am in most states, with Asian Am population and percent increase predicting completion. 2) Racial density and social network linked to substance use treatment. 3) Raw Asian Am state population not indicative of successful completion Asian Am clients more likely to complete treatment in states with higher Asian Am density and social supports.
Godinet et al. (2020-)(Godinet et al., 2020)	2016	Quantitative	AA&NH/PI	No	TEDS	N/A	1) NH/Pacific Islander (NHPI) less likely to complete treatment than Whites 2) Asian Am and Whites in outpatient treatment less likely to complete than other settings 3) Asian Am and NHPI methamphetamine users less likely to complete than White users 4) Asian Am more likely to complete treatment than Whites; 5) Methamphetamine and opiate users less likely to complete than alcohol users 6) Asian Am alcohol users had higher odds of completing treatment than users of other substances.
Garrison et al. (2019)(Garrison et al., 2019)	2006–2011	Quantitative	AA&NH/PI client discharge data-excluding methadone and inpatient/detox patients	No	TEDS	N/A	1) Asian Am outpatients have higher treatment completion rates but small effect sizes. 2) Youngest Asian Ams have highest completion rates; school important for immigrant/marginalized ethnic communities. 3) School is the most successful referral source for Asian Ams
Heaton (2018)(Heaton, 2018)	2003	Mixed methods	SYRP (youth 10–20) from 205 eligible facilities across 36 states representing five program types-detention, correctional, community-based, camp and residential treatment programs	No	Survey of Youth in Residential Placement (SYRP)	English	1) Asian Am youth had low rates of substance use during their current offense. 2) Asian Am had lower rates of SUD compared to other groups. 3) Asian Am youth were more likely to participate in community-based and camp programs. Asian Ams had the longest stay in residential placements. 4) No NH/PI youth were enrolled in programs exclusively run by substance use treatment professionals. 5) Compared to Hispanics, Asian Am were more likely to be in placements without on-site substance services. 6) Asian Am were the least likely to be in a program that screens all youth for substance use. 7) Asian Am were the most likely to be in a program that does not screen for substance use. 8) Over half of Asian Am and NH/PI were not in a program that screens all youth. 9) NH/PI youth were marginally more likely than AI/Alaska Natives to be in placements where only noncertified counselors provide services.
Bersamira et al. (2017)(Bersamira et al., 2017)	2002–2003	Quantitative	Asian Am	Yes	National Latino and Asian American Survey (NLAAS)	English, Spanish, Mandarin, Cantonese, Tagalog, Vietnamese	1) Filipinos had highest drug use rates among Asian Am. 2) US-born, proficient in English, males, young, with depression history and frequent drinkers had higher past-year drug use among all Asian Am.
Chang et al. (2017)(Chang et al., 2017)	Not report ed	Cross-sectional, Qualitative	Providers from 7 community-based substance use treatment programs serving Asian Am’s in SF Bay Area and LA	Yes	Primary data collection; 1:1 interview	N/A	1) Main substances: stimulants, alcohol, marijuana, club drugs, opioids, heroin, muscle relaxants. Providers reported methamphetami ne/cocaine most prevalent; alcohol seen as less problematic due to legality. 2) Cocaine/crack more common among poorer Asian Am clients in low-income, drug-saturated SF neighborhoods, primarily older, non-English speaking Chinese and Vietnamese immigrants. 3) Structural factors (ethnicity, age, poverty, language exclusion, time in US) influence substance use patterns. 4) Age shapes substance use patterns; younger tend to use meth/club drugs, older tend to use cocaine. 5) Majority of Asian Am clients in substance use treatment are court mandated. 6) Family dynamics can help or hinder treatment due to stigma and communication barriers. 7) Substance use treatment models may conflict with non-Christian Asian Ams’ religious beliefs. 8) Availability of staff who speak client’s primary language is key for building relationships and cultural understanding.
Sahker et al. (2017)(Sahker et al., 2017)	2000–2012	Cross-sectional, Quantitative	AA&NH/PI clients accessing substance use treatment system	No	TEDS	N/A	1. Asian Am clients’ substance use treatment admissions increasing faster than non-Asian Am counterparts. 2. Oldest and youngest clients have greater admission increases than other age groups. 3. Large increase in problematic use of prescription opioids. 4. Increase in substance use treatment admissions increasing fastest among Asian Americans who were homeless or had no source of income
Han et al. (2016)(Han et al., 2016)	2000–2002	Mixed methods	Asian Am	No	CalTOP study and Treatment Impact System (TSI) project	English	1) Asian Ams receiving residential treatment and those younger in age were overrepresented at follow-up compared to those lost to follow-up. 2) Women faced more psychological, employment, and family-related problems. 3) Men reported greater satisfaction with counselors compared to women. 4) Asian Am patients generally reported lower satisfaction with certain treatment services, such as criminal legal and family services, compared to others. 5) Asian Am women had later onset of drug use and lower education/employment rates compared to men. 6) Asian Am women more likely to be married/dependent living status, and living with someone using drugs/alcohol, while Asian Am men had more criminal involvement. 7) Asian Am men held higher expectations/responsibilities toward family and may feel more pressure to seek treatment due to stigma affecting the entire family. 8) Asian Am men reported more alcohol use, while Asian Am women reported more injection drug use. 9) Asian Am women’s traditional role as caretakers and valuing family more than themselves may explain greater drug improvement than Asian Am men after one year of treatment.
Wu et al. (2016)(Wu et al., 2016)	2005–2014	Quantitative	AA&NH/PI patients with OUD, aged older than 12	No	NSDUH	English, Spanish	1) AA&NH/PI had lower prevalence of major depressive episode and most SUDs compared to whites. 2) AA&NH/PI with OUD had low treatment use rates. 3) Adolescents, uninsured individuals, blacks, and AA&NH/PI underutilized opioid-specific treatment. 4) AA&NH/PI with OUD had low rates of using alcohol/drug treatment or opioid-specific treatment. 5) Underutilization of opioid-specific and alcohol/drug treatment. 6) Culture stigma and lack of culturally congruent addiction providers are barriers to AA&NH/PI treatment. 7) AA&NH/PI is the fastest growing segment of the US population.
Wu et al. (2015)(Wu et al., 2015)	2004–2012	Quantitative	Whites, Blacks, Hispanic s, AA& NH/PI, mixedrace individuals, and Native-Americans	No	NSDUH	English, Spanish	1) AA&NH/PI had lower major depressive episode prevalence than Whites. 2) Excluding adolescents who only used cannabis once: 5.4% among NH/PI; 16.0% of Asian-American used cannbis; the prevalence of cannabis use (≥2 days/year) varied as well: 11.9% among NH/PI to 4.5% among Asian Americans. 3) Asian Am had lower cannabis use (CU) odds than Whites, with personal, parental, or close friends’ disapproval being a significant factor (not significant among NH/PI). 3) Asian Am had highest perceived disapproval of CU and lowest prevalence of past-year CU and CU disorder, potentially due to community-level drug use activities and stigmatization.
Yu et al. (2014)(Yu et al., 2014)	2005–2008	Quantitative	Asian Am, Hispanic, non-Hispanic Black and non-Hispanic White in New York State	No	CDS	N/A	1) Asian Am report more alcohol use and have higher completion rates in treatment. 2) They are a small minority in substance use services and tend to have only one admission record. 3) Targeted prevention programs and culturally relevant resources are needed for the proportionately large group of Asian Am entering treatment for drinking-driving referrals. 4) Asian Am in substance use services are less likely to have income from public welfare and tend to start with outpatient programs through mandate.
Fang and Schinke (2013) (Fang and Schinke, 2013)	2007–2010	Quantitative	Asian Am	No	a family-based, Internet-delivered, substance use prevention program for early adolescent Asian Am girls	N/A	1) Substance use prevention for Asian Am is hindered by accessibility and equity issues, as Asian Am face barriers in accessing quality programs and are underrepresented in research. 2) A culturally generic program focused on parent-child relationships limited its ability to reach non-English speaking Asian Am families.
Lipari and Hager (2013)(Lip ari and Hager, 2013)	2003–2011	Quantitative	AA or PI aged older than 12	No	NSDUH	English, Spanish	1) Non-Hispanic Asian Am or Pacific Islanders had a lower need for alcohol or drug treatment compared to other racial and ethnic groups. 2) Asian Am or Pacific Islanders in need of treatment were less likely to receive treatment at a specialty facility compared to other racial and ethnic groups. 3) Asian Am or Pacific Islanders who did not receive treatment were more likely to not feel the need for specialty treatment compared to other racial and ethnic groups. 4) Across different age, gender, income, poverty level, and health insurance coverage groups, Asian Am or Pacific Islanders had a lower need for substance use treatment than other racial or ethnic groups.
Masson et al. (2013)(Masson et al., 2013)	Unknown	Mixed methods	Asian Am participants of substance use treatment programs in California and Hawaii	Yes	Substance use treatment programs in California and Hawaii	N/A	1) Factors examined: Peer support, CJS involvement, perceived need for treatment, family influences, culturally competent treatment, and face loss concerns. 2) Peer pressure cited as barrier, non-users seen as role models, but isolation from family can make it socially disruptive to be abstinent. 3) Structural/systems barriers hinder access to treatment. 4) Family may hinder treatment to avoid loss of face. 5) Some Asian Am groups viewed drug-using peers as hindering treatment process. Asian Am clients may only seek treatment when prosecuted for criminal offense, suggesting attempt to hide/minimize substance use.
Yu and Warner (2013)(Yu and Warner, 2013)	2005–2008	Quantitative	Asian Am in New York State	No	CDS	N/A	1) Asian Am underrepresented in substance use treatment facilities despite being 4% of US population 2) Barriers to treatment due to immigration, acculturation, language use, and cultural perspectives 3) Asian Am and Hispanics have lower readmission rates than Whites 4) Asian Am have the smallest readmission hazard and a unique low likelihood of second admission 5) Asian Am respondents prefer personal networks over formal treatment programs for SUD 6) Cultural and linguistic needs must be considered for Asian Am clients 7) Using New York as a case study may not be representative of the US
Evans et al. (2012)(Evans et al., 2012)	1999–2001 and 2003–2006	Quantitative	Asian Am	No	Two federally funded studies of patients admitted to community -based drug treatment in three states (California, Hawaii, and Montana); Methamphetamine Treatment Project (MTP) and TSI	English	1) Asian Am more reliant on others for housing 2) Asian Am more likely to use drugs, smoke, less likely to inject 3) Asian Am reported poorer health, fewer hallucinations 4) Asian Am less troubled by alcohol and medical problems, lower need for treatment 5) No difference in treatment type/length/outcomes compared to non-Asian Am 6) Similar outcomes after 1 year, lower problem severity for Asian Am in alcohol/family/medical domains
Mulvaney-Day, N. et al. (2012)(Mulvaney-Day et al., 2012)	2002–2005	Quantitative	Asian Am, Blacks, Latinos, Whites	No	NSDUH, National Epidemiologic Survey on Alcohol and Related Concerns (NESARC)	English, Spanish, (NESARC also included Mandarin, Cantonese, Korean, Vietnamese)	1) Asian Am SUD patients had more unmet need for specialty treatment than whites, but Asian Am with heavy drinking/illicit drug use had less unmet need.
Fang et al. (2011)(Fang et al., 2011)	2007	Mixed methods	Asian Am Mother-daughter dyads	No	2-year outcomes for a family-based, internet-delivered, substance use prevention program for early adolescent Asian Am girls	Not specified	1) Study challenges belief that Asian Am do not engage in substance use. 2) Peer pressure a major factor in substance use among Asian Am teens. 3) Participants reject stereotype of issue-free Asian Ams. 4) Stress, depression, low self-esteem, among reasons for Asian Am substance use. 5) Family influences seen as important by participants. 6) Community environment can impact substance use. 7) Participants call for more programs tailored to Asian Am. 8) Prevention program involving parents should target preteens/early teens.
Goebert et al. (2011)(Goebert and Nishimura, 2011)	Unknown	Mixed methods	Native Hawaiian, Asian Am, and Euro Americans (n=192)	Yes	Interviews of participants in two major residential programs in Hawaii	Not specified	1) Asian Am are less likely to seek professional help for alcohol issues compared to Euro Americans. 2) Most patients went to hospital ED for drinking-related issues. 3) Asian Am prefer acupuncture and traditional healers.
Lo and Cheng (2011)(Lo and Cheng, 2011)	2001–2003	Quantitative	Asian Am, Hispanic, Black American, White American	No	Collaborative Psychiatric Epidemiology Surveys (CPES)	English, Spanish, Mandari n, Cantonese, Tagalog, Vietnamese	1) Asian Am less likely to access specialty substance use treatment than Whites or Hispanics. 2) Asian Am have 9x greater likelihood of accessing non-specialty care for substance use disorder than Whites
Satre et al. (2010)(Satre et al., 2010)	2002–2005	Quantitative	Asian Am, Latinx, African Americans, Whites	No	Kaiser Permanent e Adult Member Health Survey (MHS)	English	1) Asian Am women least likely to fill antidepressant prescription, White women most likely. 2) Having a regular physician and being Latina or Asian Am decreased odds of filling antidepressant prescription.
Wong et al. (2010)(Wong and Barnett, 2010)	2001–2005	Quantitative	AA&NH/PI	No	TEDS 2001–2005, NSDUH 2005	N/A	1) Asian Am accounted for 1.9% of illicit drug use in U.S. adults and 1.3% of adult clients entering drug treatment for the first time 2) Asian Ams were more likely to be first-time treatment clients with stimulants being their primary drug problem (57.3%) 3) Asian Am first-time admissions had shorter drug use histories compared to other groups (13.6 days in the prior 30 days, beginning drug use at 20.7 years, and 9.4 years between start of use and first admission).
Yu et al. (2009)(Yu et al., 2009)	2005–2008	Mixed methods	Asian Am in New York State	Yes	Client Data System (CDS)	N/A	1) Asian Am prefer outpatient services over crisis centers compared to general population 2) Chinese, South Asian, Indian, Bengali, Pakistani, Korean, and Filipino Americans screened for substance use disorder, with Koreans most likely to test positive 3) Higher substance use disoder rates among Asian Am in NYC than nationwide 4) Culturally competent staff needed to provide interventions in client’s preferred language 5) Successful engagement of Asian Am clients in treatment goals higher than other outpatient clients in NYC.
Ta et al. (2008)(Ta et al., 2008)	1994–1995	Quantitative	AA&NH/PI	No	Data from Hawaii Healthy Start Program	N/A	1) Asian Am and NHPIs with depressive symptoms received fewer services than whites. 2) No significant racial differences were found in mental health/substance use service utilization based on other factors.
Niv et al. (2007)(Niv et al., 2007)	2000–2001	Quantitative	452 Asian Am and 403 non-Asian Am (matchcontrols)	No	CalTOP (California Treatment Outcome Project)	Not specified	1) Comparison group had higher alcohol and drug severity scores than Asian Am. 2) No difference in treatment retention between Asian Am and comparison group. 3) Asian Am received more legal services and fewer medical/psychiatric services compared to comparison group. 4) Asian Am received fewer overall services in their treatment program. 5) Asian Am have more stable living conditions.
Chow (2002)(Ch ow, 2002)	Not report ed	Quantitative	42 Private non-profit directors found through provider network National Asian Pacific American Families Against Substance Abuse (NAPAFASA)	Yes	Survey data from 18-page self-administer ed survey	Not specified	1) Most surveyed agencies have a long history serving Asian Am communities (5–111 years, avg 31 yrs). 2) Agencies offer diverse services including primary care, mental health, social service, and substance use. 3) Increase in mental health and substance use services. 4) ATOD budget fluctuates greatly. 5) Board of directors lacks Asian Am representation.
Harachi et al. (2001)(Harachi et al., 2001)	1989–1991	Quantitative	Non Asian Am and Asian Am	Yes	Multiple sources including California Student Substance Use Survey, Minority Youth Health in Seattle	Not specified	1) Asian Am have lower risk for drug use than other ethnic groups 2) Differences observed among Asian Am ethnic groups 3) Need to test prevention approaches for different Asian Am communities.
Morelli et al. (2001)(Morelli et al., 2001)	1992–1995	Qualitative	Asian Am (n=21)	No	Semi-structured interviews	N/A	1) Asian Am women prefer having their children with them in treatment. 2) Consistent, competent staff and culturally-sensitive professionals are important. 3) Range of substance use interventions, including cultural healing practices, is important.
Fong, R. (2000)(Fong, 2000)	1992–1995	Qualitative	Asian Am Women (n=21)	Yes	Semi structured interview with program participant s	N/A	1) 87% of women found kupuna involvement helpful 2) Kupuna aided healing through cultural practices, building skills, listening, promoting bonding, and teaching culture
Martin et al. (1993)(Martin and Zweben, 1993)	1991–1992	Qualitative	Case studies for Mien immigrants in California smoking opium	Yes	Case study data from clinic	N/A	1) Mien need to understand addiction. 2) Community support, counseling, and behavior change crucial. 3) Family ties affect treatment compliance and dropout rates. 4) Physical reasons given for opium use among Mien.
Chin et al. (1990)(Chin et al., 1990)	1983–1989	Quantitative	Chinese male patients with alcohol use disorder who are enrolled in treatment at Hamilton-Madison House	Yes	Data from treatment case files	N/A	1) Health practitioners need to educate Chinese immigrants on alcoholism and its physical effects 2) There are not enough literary and audiovisual materials on alcoholism and treatment in Chinese for the community 3) There need to be culturally sensitive detox/rehab programs as well as Chinese language inpatient services 4) New methods for detecting alcoholism need to be identified to better target education and treatment efforts 5) Increased efforts need to be placed in community educations through workshops, outreach and radio hotlines. 6) Interventions that do not cause stigmatization need to be discovered that are tailored towards the complexity of the Chinese community 7) Criteria for assessing treatment outcomes needs to reflect AUD needs 8) Need to help clients adjust to the new environment/engage in treatment schedule alongside family
Tucker, M. B. (1985)(Tuck er, 1985)	Not report ed	Mixed methods	AA&NH/PI, Black, White, Hispanic	No	Co-Occurring Disorders and Addiction Program (CODAP) Treatment and drug abuse warning network (DAWN) emergency room and death reports	N/A	1) No comprehensive reviews of ethnic minority drug use literature 2) No regular comprehensive assessments of drug use in minority populations 3) No empirical literature guiding drug treatment and prevention for minorities

These datasets also include information from programs for substance use prevention and treatment, as well as emergency room and death reports related to substance use. Covering a range of populations, including Asian Americans, Native Hawaiians, and Pacific Islanders, the datasets examine substance use, comorbidities, and treatment outcomes. The studies included in the list have examined a diverse range of populations. The most frequently studied group consists of individuals accessing substance use treatment systems, including clients discharged from treatment, patients with opioid use disorder, and participants of substance use treatment programs in California, Hawaii, and New York. Other groups studied include adolescents, Chinese male patients with alcohol use disorder, Mien immigrants (residing predominantly in southern China, northern Vietnam, Laos, Thailand, and Myanmar) in California smoking opium, and AA&NH/PI mother-daughter dyads. The studies also included comparison groups such as non-AA&NH/PI and Asian American individuals, along with other racial and ethnic groups such as White, Black, and Hispanic individuals.

3.3. Rates of Substance Use and Substance Use Disorder Among Asian Americans and Variations across Different Asian&NH/PI Ethnic Groups

Asian American individuals have lower rates of substance use and SUD compared to both White and other racial and ethnic minorities. This is consistent across studies that examined either the broader category of AA&NH/PI (Heaton, 2018) or specifically focusing on Asian Americans (Chow, 2002). Using the National Latino and Asian American Survey (NLAAS), Bersamira et al. (2017) found low rates of past-year drug use for all Asian Americans (4.6%). While specific rates were not provided, one study highlighted that methamphetamine and/or cocaine use were notably common among Asian American patients living in California, alongside other substances like alcohol, marijuana, ecstasy, opioids, heroin, and muscle relaxants (Chang et al., 2017). Factors influencing SUD rates among Asian Americans included stress, depression, low self-esteem, and disapproval of close peers and family members. Fang et al. revealed that stress, depression, low self-esteem, and various motivations like “to get high” or “to look cool” were associated with substance use among Asian Americans (Fang et al., 2011). Family dynamics played a critical role, with family support acting as a protective factor against engaging in risky behaviors. While these factors are not unique to Asian American populations, they can still influence individual behaviors and understanding their specific manifestations and addressing them within the cultural context is essential to provide effective prevention and treatment strategies tailored to the needs of this population.

Limited research has been dedicated to the study of NH/PI populations. In studies that examined NH/PI individuals separately, NH/PI exhibited a notably high prevalence of substance use. Recent research found that over 25% of NH/PI adults tested positive for alcohol use disorder, surpassing the national rate of 10.2% during the COVID-19 period (Subica et al., 2022).

3.4. Substance Use Treatment Rates

The available literature reveals a pattern of underrepresentation of AA&NH/PI populations within substance use treatment facilities. Despite the increasing Asian American population, admissions among Asian American clients have shown a faster increase compared to their non-Asian American counterparts (Sahker et al., 2017; Von Gunten and Wu, 2021; Yu and Warner, 2013). From 2000 to 2012, AA&NH/PI admissions increased 30% compared to non-AA&NH/PI admissions that decreased 0.7%. The largest surge, a 294% increase, was seen in prescription opioids among substances. Notably, the oldest age group exhibited the most significant change, with a 425% increase in admissions for individuals initiating substance use at 55 years of age and older (Sahker et al., 2017). Despite these trends, AA&NHPI continue to be less likely to seek professional help for alcohol misuse and specialty substance use treatment compared to Euro Americans and White counterparts (Goebert and Nishimura, 2011; Lo and Cheng, 2011). Among those who enter treatment, many AA&NH/PI individuals are often involved in the criminal justice system and receive court-mandated programs (Chang et al., 2017; Masson et al., 2013; Yu et al., 2014).

When examining studies specifically focused on Asian American individuals, the evidence consistently suggests that this population has limited engagement and/or access to treatment compared to other racial/ethnic groups (Alegría et al., 2022; Chang et al., 2017). Notably, Asian American individuals had the lowest treatment utilization rate at 3% (Von Gunten and Wu, 2021). Using the national level treatment system data, a higher likelihood was observed among Asian Americans to be first-time treatment clients, with stimulants like amphetamine and other nonamphetamine substances being their primary drug problem (57.3%) (Wong and Barnett, 2010). Conversely, in studies exploring NH/PI individuals at the community level, it was found that 60% of NH/PI individuals who expressed a need for treatment avoided or postponed seeking assistance (Subica et al., 2022).

Interestingly, there were differences in treatment use characteristics. NH individuals were more likely to seek treatment for both alcohol use disorder and drugs compared to Asian Americans, whereas Asian American populations were more inclined to seek treatment for drug use only (Goebert and Nishimura, 2011). Furthermore, NH/PI youth were more likely than Asian American youth to attend treatment programs without certified counselors (Heaton, 2018).

There are mixed results regarding unmet substance use treatment needs in Asian Americans compared to other groups. A national analysis by Lipari and Hager found that Asian Americans had a lower need for substance use treatment compared to other racial or ethnic groups across various demographic and socioeconomic groups, including age, gender, income, poverty level, and health insurance coverage groups (Lipari and Hager, 2013). In comparison, Mulvaney-Day et al identified differences in unmet treatment needs based on treatment type, with Asian American SUD patients having a higher unmet need for specialty treatment than Whites, but Asian Americans reporting heavy drinking and illicit drug use having a lower unmet need (Mulvaney-Day et al., 2012). Moreover, The treatment disparities within diverse ethnic groups were not explicitly addressed in the reviewed articles.

3.5. Examination of the Effectiveness of Existing Substance Use Treatment Interventions: Quality and Completion Rates

The quality and quantity of services provided in substance use treatment for AA&NHPI were generally lower compared to other racial/ethnic groups. Ta et al. analyzed data from the Hawaii Healthy Start Program and found that both groups of Asian American and NH/PI individuals with depressive symptoms received fewer number of actual mental health and substance use sessions than Whites, despite no significant racial differences in service utilization (Ta et al., 2008). Similarly, in Niv et al.’s findings from the California Treatment Outcome Project (CalTOP indicated that Asian Americans received fewer overall services in their treatment programs compared to other racial/ethnic groups (Niv et al., 2007). Using the same dataset, Han et al. found that Asian American patients generally reported lower satisfaction, particularly with auxiliary services like criminal legal and family services, compared to other racial/ethnic groups (Han et al., 2016).

Asian American and Native Hawaiians were more inclined toward a change in environment, relaxation, self-control training, and educational lectures and films compared to Whites. Furthermore, they were more than twice as likely to express a preference for seeking help from a minister, priest, or rabbi. In addition, Native Hawaiian clients demonstrated a threefold preference for marriage counseling compared to other alternatives (Goebert and Nishimura, 2011).

The studies included here present mixed results on treatment completion rates for AA&NH/PI. While Alegría et al.’s analysis of New York state-level data suggests that Asian Americans are less likely to continue treatment compared to Whites and other racial/ethnic groups (Alegría et al., 2022), Sahker et al. found that national completion rates of substance use treatment programs were higher among AA&NH/PI compared to non-AA&NH/PI in most states (Sahker et al., 2021). AA&NH/PIExamining completion rates within AA&NH/PI ethnic groups across various treatment settings yielded mixed results (Garrison et al., 2019; Godinet et al., 2020). Factors contributing to disparities in treatment completion in AA&NH/PI include neighborhood characteristics, family dynamics and cultural values influencing treatment acceptance or resistance due to stigma, social support systems, and the availability of client’s primary language in treatment settings (Alegría et al., 2022; Chang et al., 2017; Sahker et al., 2021).

3.6. Studies Disaggregating by Diverse Ethnic Groups

Table 2 includes information on identified ethnic groups, sample sizes, data collection, sampling methods, and data limitations in the eleven studies that examined diverse ethnic groups. Among Asians, Filipinos were found to have the highest rates of drug use (Bersamira et al., 2017) while Korean Americans showed a higher likelihood of testing positive for SUD in screenings compared to other Asian American groups (Yu et al., 2009). Substance use burden appears to be growing among Chinese American populations and particularly Chinese immigrants underutilize health care services, including substance use treatment (Masson et al., 2013).

Table 2.

Characteristics of studies that include subgroup ethnicity data

First Author (Year)	Studied ethnic groups	Sample size	Data collection and sampling methods	Data limitations in regards to Asian American subgroup data
Subica et al. (2022) (Subica et al., 2022)	Polynesian, Micronesian, Melanesian/other	327	Cross-sectional survey conducted from April to November 2021. Three recruitment pathways: personalized e-mail outreach, telephone calls, and in-person at NH/PI congregation sites. Adults offered two survey options with a $20 incentive: online survey via Qualtrics or paper-and-pencil survey administered by NH/PI research staff (interview offered for participants with limited English proficiency).	Use of non-probability sampling, challenges in generalization of findings
Bersamira et al. (2017) (Bersamira et al., 2017)	Filipino, Chinese, Vietnamese, other Asian Am	2087	Cross-sectional epidemiological survey that was conducted in 2002–2003. The study sample was collected from Asian Americans living in all 50 states and the District of Columbia utilizing a survey instrument that was available in English, Cantonese, Mandarin, Tagalog, Vietnamese, and Spanish.	“Other Asian Am” category is hard to interpret; Interviewers were able to cover the following Asian languages: Chinese, Vietnamese, or Tagalog
Chang et al. (2017) (Chang et al., 2017)	Chinese, Vietnamese, Cambodian, Filipino, other	40	Interviewed 40 treatment providers from 7 community-based substance use treatment programs in SF Bay Area and LA who work with AA&NH/PI clients. Specific programs were included to ensure representation of diverse AA&NH/PI communities	Provider recall bias may exist; sample comprises individuals receiving services from publicly funded treatment programs, with a substantial number referred from the criminal justice system.
Wu and Blazer (2015)(Wu, L.T. and Blazer, D.G., 2015)	Chinese, Filipinos, Asian Indians, Vietnamese, Koreans and Japanese Americans	343850	Combined data from PubMed and Google Scholar search using keywords “Asian Am, Native Hawaiians, Pacific Islanders, substance use, alcohol use, marijuana use, drug use, SUD, substance use treatment and comorbidity. (Includes TEDS, NSDUH, US Census, etc.)	Lack of data in general particularly pertaining to underrepresented ethnic groups
Masson et al. (2013) (Masson et al., 2013)	Filipino, Chinese, Vietnamese, Japanese, Korean, Native Hawaiian, other Asian Am ethnicity, multiple ethnicities	61	Semi-structured interview with participants about treatment experiences and that of their friends; Individuals enrolled in substance abuse treatment were recruited through flyers posted and distributed by clinicians within the treatment programs.	Limited sample size per ethnic group, especially for monolingual Vietnamese-speaking and monolingual Chinese-speaking individuals
Goebert et al. (2011) (Goebert and Nishimura, 2011)	Native Hawaiians	192	Individuals at two Hawaii residential treatment programs were asked during orientation if they were interested in participating in a research project via interviews.	Limited sample size to analyze Japanese American and Filipino American participants separately, so they were grouped as Asian American.
Yu et al. (2009) (Yu et al., 2009)	Chinese, South Asian (Indian, Bangladeshi, Pakistani), Korean, Filipino, Japanese, Vietnamese, Thai, Other identified (Cambodian, Laotian, Pacific Islander), Other unidentified	5621	2 treatment sites in New York Crity; GPRA Client Outcomes Measures Tool, which was translated to Chinese, Korean, Hindi, and Bengali.	Difference in “Other identified group” (Cambodian, Laotian, Pacific Islander) versus “Other unidentified group”; As Pacific Islanders constitute less than 1% of the study samples, the results exclusively apply to the Asian American population.
Chow (2002)(Chow, 2002)	Chinese, Vietnamese, Cambodian, Japanese, and Laotian	24 agencies	Self-administered physical survey instrument, primary data collection done by respondent (Directors of programs); Identification of potential survey participants was done through substance abuse and/or mental health service providers catering to AAPI clients in 12 states with significant AAPI populations (California, Colorado, Connecticut, Georgia, Illinois, Massachusetts, North Carolina, New York, Oregon, Texas, Utah, and Washington).	Respondent recall bias may exist
Harachi et al. (2001)(Harachi et al., 2001)	Chinese, Filipino, Japanese, Korean, Pacific Islander, Southeast Asian	1003	Data harmonization across studies using California Student Substance Use Survey data	Grouping of several cultural groups into this South East Asian category, for example, Vietnamese, Cambodian, Laotion, Hmong, and Mien
Martin et al. (1993)(Martin and Zweben, 1993)	Laotian	2	Specific to one clinic in Oakland serving Mien opium users, convenience sampling; Meetings were orchestrated by community mental health workers, fostering collaboration between clinic personnel and Mien leaders.	N/A
Chin et al. (1990)(Chin et al., 1990)	Chinese	70	Specific to 1 outpatient treatment center; Excluded patients who did not complete treatment and patients of different ethnicities; also interviewed former and current CAS staff members.	N/A

Commonly included ethnic groups were Filipinos, Vietnamese, Chinese, Korean, and Japanese. The sample sizes of studies ranged from qualitative case studies with two individuals to aggregated national-level datasets. Data collection methods included national, population-level datasets such as the NSDUH, community-level, cross-sectional epidemiological surveys, systematic reviews, and treatment-center based qualitative interviews. Diverse recruitment strategies were noted. Subica et al. focused on recruiting Pacific Islander ethnic groups through personalized e-mail outreach, telephone calls, and in-person engagement at congregation sites (Subica et al., 2022). Bersamira et al. conducted a nationwide cross-sectional epidemiological survey encompassing Filipino, Chinese, Vietnamese, and other Asian American ethnic groups, employing survey instruments available in multiple languages (Bersamira et al., 2017). These studies highlight the importance of tailored recruitment strategies, ranging from surveys and interviews to leveraging community networks, to capture the nuances within the AA&NH/PI population and address potential limitations in data collection.

Some noted limitations included the lack of data collection in non-English languages, small sample sizes hindering further analysis by important socioeconomic and demographic characteristics, and concerns about generalizability outside of study sites. Concerns were raised regarding ethnic group-level analysis, specifically regarding data availability and the grouping of diverse ethnic and cultural groups.

3.7. Data Limitations

Data availability was identified as a general limitation when examining Asian Americans and the ethnic groups, highlighting the need for more comprehensive data on underrepresented ethnic groups. Table 2 shows studies reporting subethnic group data while Table 3 lists studies using combined data on AA&NH/PI populations. The practice of grouping of diverse ethnic and cultural groups under the term “other Asian group” continues to obscure important nuances and differences among them. There is a clear need to distinguish Asian Americans, Native Hawaiians, and Pacific Islanders to avoid misinforming research and policy.

Table 3.

Studies and datasets that aggregate Asian American with Native Hawaiian, and Pacific Islander data

First Author (Year)	Year(s) of study	Dataset/Method for collecting data
Nguyen et al. (2022)(Nguyen et al., 2022)	2011–2021	HHS surveys and data systems, including those developed by the National Center for Health Statistics and CMS, along with previous work examining disaggregated AA&NH/PI data collection.
Sahker et al. (2021)(Sahker et al., 2021)	2006–2017	TEDS
Godinet et al. (2020-)(Godinet et al., 2020)	2016	TEDS
Garrison et al. (2019)(Garrison et al., 2019)	2006–2011	TEDS
Sahker et al. (2017)(Sahker et al., 2017)	2000–2012	TEDS
Wu et al. (2016)(Wu et al., 2016)	2005–2014	NSDUH
Wong et al. (2010)(Wong and Barnett, 2010)	2001–2005	TEDS 2001–2005, NSDUH 2005
Ta et al. (2008)(Ta et al., 2008)	1994–1995	Data from Hawaii Healthy Start Program
Tucker, M. B. (1985)(Tucker, 1985)	Not reported	Co-Occurring Disorders and Addiction Program (CODAP) Treatment and drug abuse warning network (DAWN) emergency room and death reports

Furthermore, one study calls for policy support to invest in expanding sample sizes within the Asian American racial and ethnic category to ensure more robust and representative research findings. Concerns about potential selection bias and challenges in disaggregating data were raised by certain studies using secondary data, impacting the quality and applicability of the research. Additionally, the research using administrative TEDS data highlights the exclusion of certain states and limited representation of Asian populations in federally-funded treatment services (Chang et al., 2017).

Challenges associated with primary data collection and reporting for AA&NH/PI populations further complicate the research landscape. Some studies mention limitations related to self-reported data, stigma, limited English proficiency, lack of individual ethnic group information, and small sample sizes, collectively hindering the generalizability and reliability of the findings (Fang et al., 2011; Goebert and Nishimura, 2011; Lo and Cheng, 2011; Masson et al., 2013; Ta et al., 2008). These considerations underscore the importance of further research to address these limitations and provide a more nuanced understanding of substance use among specific racial and ethnic groups.

4. Discussion

This systematic review serves as a comprehensive synthesis of current literature, shedding light on substance use and treatment disparities among Asian Americans, Native Hawaiians, and Pacific Islanders. The article attempted to disaggregate findings reported for AA, NH/PI, and specific AA&NH/PI ethnic groups where possible. Additionally, the article reported on disaggregated analyses of AA&NH/PI ethnic groups. The included studies cover a wide range of topics related to the substance use and SUD prevalence, unique patterns of substance use among ethnic groups, substance use treatment admissions, demographics, predictors of treatment completion, and perspectives of treatment providers on AA&NH/PI patient experiences. The studies aimed to examine disparities in substance use treatment for AA&NH/PI populations, address the underutilization of treatment services, explore cultural factors influencing treatment outcomes, and identify trends in data collection related to AA&NH/PI populations.

4.1. Summary of Findings

The findings indicate that, in general, AA&NH/PI individuals exhibited lower rates of substance use and SUD compared to other racial and ethnic groups. However, there were variations in reported substance use patterns among different AA&NH/PI ethnic groups, with varying rates of substance use and SUD across different datasets. Notably, higher rates of substance use were observed among NH/PI populations. Filipino-Americans have been found to have higher drug use rates among Asian Americans, indicating the importance of targeted interventions for this ethnic groups (Bersamira et al., 2017). Our study results align with previous research demonstrating when NHs/PIs are disaggregated from AAs, a notably high prevalence of substance use among NHs/PIs is revealed (Wu, L.-T. and Blazer, D., 2015). While studies generally show underrepresentation of AA&NH/PI populations in substance use treatment facilities, specific nuances emerge when examining distinct groups within this population.

AA&NH/PI populations face significant disparities in accessing and utilizing substance use treatment services. Underutilization of health care services is pervasive amongst Asian American for multiple health conditions (Doan, 2023), and is also the case for SUD treatment; AA&NH/PI are underrepresented in treatment settings. In terms of substance use treatment use, Asian American individuals had limited engagement and access to treatment, marked by a low treatment utilization rate of 3% (Von Gunten and Wu, 2021). NH/PI individuals were also less likely to seek professional help, with 60% avoiding or postponing treatment (Subica et al., 2022). The quality and completion rates of substance use treatment for AA&NH/PI individuals were generally lower than those for other groups, influenced by factors such as neighborhood characteristics, family dynamics, cultural values, and language barriers. Studies that disaggregate diverse ethnic groups within the AA&NH/PI population highlight varying rates of substance use among Filipino, Vietnamese, Chinese, Korean, and Japanese individuals. It is worth noting that while studies more commonly report outcomes for larger Asian American ethnic groups like Chinese, Filipino, Japanese, Korean, and Vietnamese (as mandated by Office of Management and Budget), there remains a substantial gap in our knowledge regarding substance use, SUD, and substance use treatment within smaller Asian American ethnic groups. Similarly, for NH/PI populations, we observed a comparable trend wherein Native Hawaiians, the largest NH/PI group, were studied more frequently compared to other PI groups.

4.2. Improving Substance Use Treatment Access and Outcomes by Addressing Data Limitations

Addressing the disparities in substance use treatment access and outcomes among AA&NH/PI populations requires a multifaceted approach, including addressing data limitations. It is essential to disaggregate data by Asian American ethnic groups to identify ethnic group-specific needs and develop targeted interventions. Given that cultural norms, stigma, language barriers, and lack of culturally competent services influence treatment disparities, it is essential to implement culturally sensitive prevention efforts and increase awareness and accessibility of treatment services (Butler et al., 2016). This can be achieved by improving cultural competency training for healthcare providers, hiring diverse team members representing the communities of interest, fostering community support systems, and tailoring substance use treatment programs to meet the cultural and linguistic needs of Asian American clients (Fong, T.W. and Tsuang, J., 2007).

Providers should be cognizant of risk factors that are specific to Asian Americans, such as social class, substance use, and age, avoiding the endorsement of model minority stereotypes and providing culturally tailored treatment (Sahker et al., 2017). Disaggregation of the AA&NH/PI data allows for the consideration of intersectionality, taking into account factors such as age and gender, and the adoption of age-sensitive and gender-sensitive approaches to examining disparities. For example, Asian American women may have preferences for treatment that involve having their children with them while in substance use treatment (Fang et al., 2011).

4.3. Improving Substance Use Treatment Access and Outcomes by Developing Targeted Interventions

Our study highlights implications for future intervention development and programming. There is a need for the development of culturally sensitive detox/rehab programs and the availability of inpatient services in Asian languages (Fang et al., 2011). Task-sharing interventions, such as involving Community Health Workers (CHW), peer-led support groups, and peer recovery coaches, offer potential solutions to address the shortage of Asian-speaking providers (Kormendi and Brown, 2021). Family interventions have proven effective in substance use prevention within this population,strengthening protective factors like family bonding, promote healthy parent-child communication, and provide support for individuals at risk (Fang and Schinke, 2013). By involving family members in substance use intervention programs, a supportive environment for recovery and prevention can be created. Finding interventions that are tailored towards the unique experiences and challenges of the AA&NH/PI communities, without worsening stigmatization, is crucial in addressing these disparities effectively. Providing supportive environments that accommodate these preferences and ensuring consistent, competent staff and culturally-sensitive professionals can enhance treatment engagement and effectiveness. Additionally, regional demographic and healthcare use information may offer valuable insights into the service needs of Asian American populations (Chang et al., 2017). For instance, states with decreased Asian American admissions but large Asian American populations could benefit from community-based outreach programs and screenings. Treatment providers can collaborate with other resources to address the needs of specific groups, such as low-income individuals, at-risk adolescents and seniors, and those with co-occurring medical conditions.

4.4. Improving Substance Use Treatment Access and Outcomes at the Policy-Level

There are additional policy approaches that can advance our knowledge of and interventions for Asian Americans with substance use disorder. First, requiring non-English language data collection in national surveys like NSDUH, including languages such as Mandarin, Cantonese, Vietnamese, Korean, Tagalog, or Hindi, is crucial to ensure that limited English proficiency does not hinder accurate representation. Second, policies that encourage community-based support networks can facilitate access to treatment. These may include funding for community organizations that provide culturally sensitive support services, outreach, and education. Encouraging diversity in the healthcare workforce, including more Asian American healthcare professionals, can enhance cultural competency and improve the overall quality of care for Asian Americans with substance use disorder. Next, there is a need to challenge the “Model Minority Myth” in policymaking and research to ensure that disparities are recognized and resources, including NIH funding, are allocated more effectively for SUD interventions among Asian Americans. Finally, expanding health insurance coverage, increasing funding for treatment programs, and reducing barriers to care are also important steps in making substance use treatment more accessible and affordable for Asian Americans (Fang et al., 2011).

4.5. Implications for Future Research

Our study also poses implications for future research. There is a need for further investigation to deepen our understanding of substance use, SUDs, and treatment disparities among Asian American youth and elderly populations. Given the significance of the age life course approach in understanding substance use and treatment use (Hser et al., 2007), there is a pressing need for additional research in this area. In terms of research methodology, collecting comprehensive data on substance use patterns and treatment utilization among AA&NH/PI ethnic groups is crucial to capture the diversity within the population. Current approaches to aggregating AA&NH/PI ethnic groups when conducting research masks heterogeneity between diverse populations. Second, exploring the factors contributing to treatment disparities, such as cultural norms, stigma, and language barriers, is crucial. Longitudinal studies can provide insights into the trajectories of substance use and recovery outcomes.

There are limited studies focusing on the Asian American population as a racial group, and there is a lack of research on Asian American adults entering substance use treatment and their long-term outcomes (Niv et al., 2007). Some authors cautioned that broad definitions of treatment utilization may not accurately reflect the treatment gap or specific needs of Asian American populations seeking substance use treatment services (Sahker et al., 2022). The presence of mandated clients among Asian American individuals in treatment further complicates the comprehensive understanding of this population. Incomplete program information, potential biases in selecting court-referred participants, and a lack of understanding regarding treatment can all contribute to this complexity (Evans et al., 2012; Masson et al., 2013). It would be valuable to untangle the influence of culture, recency of immigration, and geographic location, as these factors may have an impact on rates of substance use. By examining these elements separately, we can gain a better understanding of their individual contributions and how they intersect to shape patterns of substance use and SUD. Additionally, language and cultural barriers complicate research efforts as well, limiting access for individuals who may not be fluent in the study language or adequately addressing cultural nuances, and limiting the available data to examine disparities and prevalence of SUD in the first place. However, the scarcity of research validating substance use screeners in languages specific to diverse ethnic populations underscores the critical necessity for future investigations dedicated to the development and refinement of these assessment tools. Addressing this gap requires a concerted effort to create, test, and adapt screeners for diverse languages, considering the linguistic and cultural intricacies within this community (Choi et al., 2023).

Additionally, a lack of distinction exists between AA&NH/PI. While this article aims to discern trends within the Asian American population, existing literature often conflates Asian American, Native Hawaiian, and Pacific Islander groups. Notably, datasets like TEDS employ three categories: 1. Asian OR Pacific Islander, 2. Native Hawaiian OR Other Pacific Islander, and 3. Asian. Despite the rich diversity within the Asian American and Native Hawaiian/Pacific Islander communities, they are frequently aggregated. This not only results in an inaccurate representation of unique challenges and disparities but also diminishes the recognition of distinct cultural experiences. Such tendencies, compounded by existing stigmas and stereotypes surrounding SUD within diverse cultures, can hinder the advancement of research for AA&NH/PI. We acknowledge the inherent challenges when dealing with disaggregated data (Nguyen et al., 2022; Shimkhada et al., 2021), particularly when advanced research methods are required. These challenges are accentuated when exploring the intersection of multiple dimensions of identity, including ethnicity, gender, and socioeconomic status. Utilizing non-cross-sectional methods, for example, necessitates larger sample sizes to provide sufficient statistical power for meaningful conclusions. Likewise, incorporating various dimensions of identity, such as gender, socioeconomic status, and immigration status, will further increase the complexity and the need for larger, more diverse samples.

Stigma and stereotypes surrounding SUD and help-seeking behaviors within AA&NH/PI cultures contribute to underreporting and reluctance to participate in sensitive research topics. The ongoing cycle of restricted healthcare access, inadequate substance use treatment, and the historical underrepresentation of Asians in research persists, further reinforcing their marginalized status. Given the COVID-19 pandemic and increase in anti-Asian hate and discrimination, future research might focus on the relationship between COVID-19 related discrimination and SUD as well (Subica et al., 2022). Although the studies reviewed here did not directly examine the influence of racism and discrimination, prior research has indicated their significant roles in shaping substance use patterns among AA&NH/PI. For instance, Asian Americans who reported experiencing unfair treatment had higher odds of having a history of alcohol use disorder (Chae et al., 2008; Yoo et al., 2010).

Future research efforts should continue to explore these associations to better understand the complexities of how racism and discrimination can impact substance use treatment access and retention. It is important to note that limited data sets explicitly measure these variables, emphasizing the need for further exploration in this area of study. Additionally, emphasizing the need for clinicians to address potential racism and microaggressions in treatment, alongside language barriers, is important for providing equitable care. Clinicians must be aware of their biases and work to prevent discriminatory behaviors, ensuring better patient experiences and outcomes in diverse populations. Finally, recognizing intersectionality and acknowledging the diverse ethnic group differences within the Asian American population can provide a more nuanced understanding of substance use disparities. This understanding can guide the development of targeted interventions specifically tailored to address the unique needs of different ethnic groups. It is important to evaluate the impact of these culturally tailored interventions to ensure their effectiveness in reducing disparities and promoting positive outcomes among the Asian American population. Policymakers and community leaders can work towards increasing access to culturally competent and linguistically appropriate treatment services, reducing barriers to help-seeking, promoting community engagement, and addressing systemic issues that contribute to disparities in substance use treatment.

4.6. Limitations

While this systematic review has provided valuable insights, it is important to acknowledge the potential limitations of the review process, such as the exclusion of non-English articles and the reliance on published literature, which may introduce publication bias. Despite the importance of disaggregating AA&NH/PI groups, it is noteworthy that a number of the studies and datasets included in this analysis still aggregate these groups. This aggregation limited our ability to assess disparities and highlights the need for better data collection and reporting. Additionally, it is important to recognize the existing bias in datasets that were used in these reviewed articles, which tend to focus primarily on English and Spanish speakers. This limitation could hinder our ability to fully comprehend the extent of estimating the prevalence of substance use and SUD within the diverse Asian ethnic groups. Thus, efforts should be made to expand data collection to encompass a broader linguistic and cultural spectrum, ensuring a more inclusive and nuanced approach to addressing SUD among diverse ethnic groups.

5. Conclusion

In conclusion, this systematic review reveals the nuanced landscape of substance use and treatment disparities among AA&NH/PI populations. The review underscores the importance of disaggregating data to reveal distinct patterns within various ethnic subgroups. In light of the identified data limitations in this review, it becomes evident that targeted interventions and strategic data collection, including comprehensive assessment of ethnic groups, are essential to effectively address substance use disparities, improving treatment access, and enhancing outcomes for AA&NH/PI communities. By recognizing and addressing these data limitations, future research can develop more informed strategies to meet the specific needs of individual communities in relation to substance use and treatment disparities. This approach will contribute to the overall improvement of health outcomes and well-being among AA&NH/PI, promoting equitable access to substance use prevention, treatment, and recovery services. Through collaborative efforts, policymakers, healthcare professionals, and researchers can work together to bridge the gaps in data and interventions, ensuring health equity for all populations.

Highlights.

• Underrepresentation of AA&NH/PI in substance use treatment facilities persists.

• Treatment quality and completion rates are lower among AA&NH/PI.

• Limited culturally competent treatment options are available for AA&NH/PI.