ORIGINAL RESEARCH ARTICLE
Davis Chhoa, BA1, Niet Khay2, Judy Young, BA3, Malathi Srinivasan, MD4 and N. Ewen Wang, MD5
1Stanford University School of Medicine, Stanford, CA, USA; 2Stanford University, Stanford, CA, USA; 3Southeast Asian Development Center, San Francisco, CA, USA; 4Department of Medicine, Division of Primary Care and Population Health, Stanford University School of Medicine, Stanford CA, USA; 5Departments of Emergency Medicine and Pediatrics, Stanford University School of Medicine, Palo Alto, CA, USA
Background: The COVID-19 pandemic has exacerbated many social determinants of health and barriers to health care for Southeast Asian Americans.
Objective: The objective of this study is to understand the impact of the COVID-19 pandemic on Southeast Asian American communities’ health care utilization and need for support.
Methods: This cross-sectional, multiple methodology study administered surveys and conducted focus groups with 78 participants (≥14 years) across generations and Cambodian, Laotian, and Vietnamese ethnicity in partnership with the Southeast Asian Development Center in San Francisco, California between July and September 2021.
Results: We identified two themes in health care utilization: 1) language and technology barriers were magnified during the pandemic, while telehealth options increased access options; 2) fear of anti-Asian violence deterred participants from public outings and activities; two themes in the role of community and community centers: 1) intergenerational support facilitated health care access; 2) community centers provided crucial social services; two themes in COVID-19 prevention: COVID-19 safety precautions contributed to interpersonal conflict and financial stress and 2) lack of linguistically accessible COVID-19 information and services posed challenges to COVID-19 testing and vaccination.
Conclusions: Despite the challenges posed by the duality of the COVID-19 pandemic and fear of anti-Asian violence, Southeast Asian Americans persisted with resilience to seek health services with intergenerational support and the guidance of community centers. This highlights the need for further expansion of culturally relevant, linguistically accessible, and trauma-informed health interventions and enhanced support for community-based organizations in advancing health for these underserved populations.
Key Words: COVID-19 ◾ Asian Americans ◾ Southeast Asian Americans ◾ health access ◾ immigrants
Citation: Journal of Asian Health, 2024;16:e58
Copyright: © 2024 Journal of Asian Health, Inc. is published for open access under the license Creative Commons CC BY-NC 4.0 License. Authors have full copyright.
Competing interests and funding: The authors have no relevant financial or nonfinancial interests to disclose. This work was supported by the Stanford Medical Scholars Research Program Fellowship, the Stanford Center for Asian Health Research and Education Grant, and the Stanford University of School of Medicine, Department of Emergency Medicine.
Correspondence to: Davis Chhoa, BA, 291 Campus Drive, Stanford, CA 94305, USA. Email: dchhoa@stanford.edu.
The COVID-19 pandemic has drastically impacted vulnerable communities across the world, including Asian Americans, causing many to suffer social, economic, and health consequences during this tumultuous period.1,2 As of March 2022, the United States has had over 79 million cases and over 976,000 deaths due to COVID-19.3,4 According to national data, Asian Americans have had some of the lowest number of COVID-19 cases and deaths compared to Hispanic and Black populations.3,5 However, early reports highlighted that Asian Americans account for almost half of COVID-19 deaths in San Francisco and Chinese Americans are 1.5 times more likely to die from COVID-19 than non-Hispanic Whites in New York City.6,7 Prior to the COVID-19 pandemic, only 0.17% of funding from the National Institutes of Health for clinical research focused on Asian American, Native Hawaiian, and Pacific Islander participants, highlighting the gap in structural support for Asian -American health research that was further widened during the pandemic.8 The lack of disaggregated COVID-19 data among Asian American ethnic groups at national and local levels has made it difficult to fully understand how the pandemic has impacted the health of this heterogeneous population, leading to the invisibilization of disparities among the Asian American population.9–11
The COVID-19 pandemic brought about a concurrent wave of increased discrimination and violence against Asian Americans.12 From March 2020 to December 2021, there were 10,905 hate incidents against Asian Americans reported to Stop Asian American Pacific Islander Hate, with undoubtedly many more occurrences unreported.13 The widespread fear due to these increased hate incidents may have deterred Asian Americans from seeking and receiving adequate health care in addition to having profound mental health impacts on Asian Americans.14,15 The limited studies available report detrimental effects of racial discrimination during the COVID-19 pandemic on self-reported increases in anxiety, depressive symptoms, and sleep difficulties among Asian American participants.16,17
Within the Asian American population, Southeast Asian Americans (including Cambodian, Laotian, and Vietnamese) have reported lower health care access and utilization rates, partially due to the lack of linguistically and culturally competent health services.18,19 Many have endured a history of conflict and violence during the wars and political turmoil in Southeast Asia prior to immigration to the US In the context of being uprooted from their homelands and essentially restarting their lives in the United States, many Southeast Asian Americans faced significant barriers to health care access, such as language and culture, health literacy, health insurance, and immigrant status prior to the COVID-19 pandemic.18–20
This community-based research study partnered with a local community organization in the Tenderloin district of San Francisco, California that predominantly serves Cambodian, Laotian, and Vietnamese community members. Therefore, this study sought to understand disparities in health care experiences among Cambodian, Laotian, and Vietnamese Americans in the San Francisco Bay Area during the COVID-19 pandemic. The findings will help guide recommendations for community-based organizations to improve health outcomes of Southeast Asian Americans. We hypothesize that the first-generation participants across each ethnic subgroup will face more challenges in healthcare access compared to second-generation participants due to exacerbations of known barriers, such as language access, while increased racial discrimination and violence towards Asian Americans will perpetuate fear in accessing health care services among all participants.
The study utilized a mixed research methodology to investigate community experiences and perceptions towards health care utilization and the impact that fear of anti-Asian violence had on health-seeking behaviors during the COVID-19 pandemic between July and September 2021.
The study was conducted in the San Francisco Bay Area, a region with a total population of more than 7.7 million people, of which approximately 27% are Asian American.21 In March 2020, the Bay Area was the first major metropolitan area in the US to enact public health orders against the spread of COVID-19 and has maintained a relatively low record of COVID-19 cases throughout the pandemic compared to other metropolitan areas.22,23
We collaborated with the Southeast Asian Development Center, a nonprofit community organization that serves Cambodian, Laotian, and Vietnamese communities in San Francisco Bay Area. Southeast Asian Development Center provides a variety of services, including youth programs, workforce development services, translation services, and basic needs resource navigation. Community leaders of each generational group and ethnicity identified potential participants for the study. We recruited 78 participants based on their age (14 years or older) and self-identification as Cambodian, Laotian, or Vietnamese. The participants were grouped into focus group cohorts by generational status (first-generation, born elsewhere, and immigrated to the US after childhood, or second-generation, born and/or lived primarily in the US since childhood) and by ethnicity (Cambodian, Laotian, or Vietnamese).24 Participants were offered a gift card as an incentive for study participation. Each participant was limited to participating in one focus group to ensure fair distribution of limited participation incentives to all interested participants.
The study was granted approval by the Stanford University Institutional Review Board (May 12, 2021, #60712). Informed consent was obtained from all individual participants included in the study, and written informed consent was obtained from parents or guardians of participants who were under 18 years of age.
The objectives of the surveys were to obtain descriptive data to characterize study participants and to collect quantitative data about participants’ experiences of healthcare access and utilization. Participants completed an anonymous survey in English or in Khmer (Cambodian), Laotian, or Vietnamese with the assistance of a translator. The survey questions were adapted from standardized questionnaires and other published studies and were tested and revised for clarity before administration.25,26 The survey included questions about participant demographics, health care utilization, and access to COVID-19 testing and vaccination in the last 12 months prior to survey participation (Tables 1 and 2).
The objectives of the semi-structured focus groups were to collect qualitative data on participants’ perspectives and experiences on how the COVID-19 pandemic affected their health care access and utilization and the impact that fear of anti-Asian violence had on health-seeking behaviors. The focus groups were conducted in-person or remotely via Zoom based on the pandemic health restrictions, interpretation needs, and preferences of participants, and lasted 30–90 min each. The first-generation focus groups were conducted in-person to offer language interpretation to limited English proficient participants, to address limited technology skills, and to facilitate participant comfort in a familiar community space. The second-generation focus groups were conducted remotely via Zoom to provide increased flexibility and convenience to participants with school, work, or childcare responsibilities. Six first-generation focus groups were conducted in-person at community spaces, while nine of the second-generation focus groups were conducted remotely (Table 3).
The first-generation focus groups were co-facilitated by the lead author of the research study and a community leader from each ethnic community who were fluent in English and Khmer, Lao, or Vietnamese, respectively. The community leader in each first-generation focus group offered live interpretation of focus group questions and responses between the first author (DC) and participants at the in-person focus groups. The second-generation focus groups were facilitated virtually by the first author (DC) of the research study without interpretation as all second-generation participants were fluent in English.
The focus groups were audio recorded, transcribed, and checked for quality and completeness. The codebook utilized for qualitative analysis was developed using both deductive and inductive approaches based on the data and an adapted health services framework and was iteratively refined until the team agreed on the final codebook (Figure 1).27,28 Themes were then mapped and interpreted. The coding software, Dedoose, was used to organize and facilitate the qualitative analysis process.
Figure 1. Adapted conceptual framework of Asian American immigrant health utilization during COVID-19 pandemic.21,22
Seventy-eight participants, 47 first-generation participants (16 Cambodian, 16 Laotian, and 15 Vietnamese), and 31 second-generation participants (9 Cambodian, 14 Laotian, and 8 Vietnamese) participated in surveys and focus groups. Participants engaged in the study in English (40%) or with the assistance of Khmer (20%), Lao (20%), and Vietnamese (20%) interpreters.
First-generation participants ranged in age from 35 to 82 years (mean age 63.8 years, SD 11.1 years) (Table 1). The median ages of first-generation participants from each ethnic group were 67 years (Cambodian), 68 years (Laotian), and 61 years (Vietnamese). The average number of years since immigration to the US was 22.9 years (SD 14.6 years). All first-generation participants spoke their origin country’s language as their primary language and only 28% of first-generation participants had a self-reported ‘well’ or ‘very well’ English proficiency. Sixty-two per cent of first-generation participants rated their current health status as fair or worse (28% poor, 34% fair) (Table 2). Eighty-two per cent of first-generation participants had been tested for COVID-19 at least once, and among those, 21% had tested positive for COVID-19. Ninety-eight per cent had received at least one COVID-19 vaccine.
Second-generation participants ranged in age from 14 to 50 years (mean age 25.3 years, SD 12.5 years) (Table 1). The median ages of second-generation participants from each ethnic group were 22 years (Cambodian), 40.5 years (Laotian), and 15.5 years (Vietnamese). Among second-generation participants, 61% were born in the United States. Fifty-five per cent of second-generation participants speak English as their primary language and 87% report ‘well’ or ‘very well’ English proficiency. Ten per cent of second-generation participants rated their current health status as fair or worse (Table 2). Sixty-five per cent of second-generation participants had tested for COVID-19 at least once, and among those, 20% had tested positive for COVID-19. Ninety-seven per cent had received at least one COVID-19 vaccine.
When asked about barriers to accessing health care, first-generation participants overwhelmingly described difficulties with language access and technology barriers (Table 4). While many first-generation participants expressed that remote or staff interpreters were generally available when accessing medical services, the quality and convenience of language access varied throughout the health care process and by clinic and native language spoken. Participants who spoke Khmer or Lao observed long wait times for an available interpreter at clinics compared to Vietnamese-speaking participants. First-generation participants highlighted the differences between speaking and being literate in their native language and perceived barriers in completing health care forms or understanding written communications about their health care. Most first-generation participants relied on their families, friends, or community centers for language assistance if interpretation or translation services were unavailable.
Many first-generation participants shared frustrations with the technological skills needed to obtain health care and highlighted the need for tech literacy to utilize patient portals or check-in kiosks in clinics. First-generation participants faced further technology barriers to accessing health services during the COVID-19 pandemic when most ambulatory and elective medical care abruptly shifted to remote, telehealth services. Some participants relied on family members to help them participate in telehealth visits, while other participants deferred their health care until clinic appointments were available again. Even if participants were able to access telehealth visits, some participants preferred clinic visits to be able to be physically examined and decreased their trust in health care providers on telehealth visits.
Second-generation participants shared challenges of navigating health insurance and transportation barriers. Many participants’ lack of knowledge about health insurance processes and the logistical burden of navigating health insurance plans created barriers to utilizing health services. Among participants who were uninsured, some described hesitancy to seek medical care due to fear of exorbitant medical bills. In addition, participants highlighted the unreliability of public transportation and financial burden of transportation deterring them from seeking medical care. Some suggested their preference for telehealth visits if available to overcome transportation barriers.
Across ethnicities and generations, participants highlighted the impact that fear and anxiety about anti-Asian violence has had on their daily lives and health-seeking behaviors (Table 4). Participants mentioned several incidents of physical assault towards community members they personally knew. Both first-generation and second-generation participants expressed that fear of anti-Asian violence occurring to themselves or their families has created a sense of ‘hyper-awareness’ when going out in public. First-generation participants mentioned that they would alter plans to go out earlier during the day or when a family member could accompany them or would employ strategies to avoid being identified as Asian. In contrast, second-generation participants were unlikely to change medical appointments or plans deemed necessary but maintained vigilance when out in public. Second-generation participants expressed greater concern about older community members being victims of anti-Asian violence than their own personal safety.
Intergenerational community was an underlying theme that spanned multiple topics and was discussed by both first- and second-generation participants (Table 4). First-generation participants heavily relied on younger family members for language interpretation and help with accessing online resources and navigating telehealth. Many first-generation individuals needed family members to accompany them to necessary appointments and other medical services. However, due to the COVID-19 pandemic limiting the number of visitors allowed, accessing service became more difficult for first-generation participants. Second-generation participants discussed experiences of acting as interpreters and caretakers and facilitating crucial communications between their elder family members and necessary health resources. Despite the desire to support their families, second-generation individuals faced significant strain and burden from assuming these roles. However, COVID-19 limited second-generation participants from accompanying their family members to provide interpretation and emotional support was frustrating to them as well.
Throughout the duration of the COVID-19 pandemic, both generations experienced higher levels of stress from feelings of concern for the other. First-generation participants were worried about the health and safety of their children and grandchildren, while second-generation participants worried about the health and safety of their elder family members with the rise of anti-Asian hate targeting vulnerable, elderly Asian-Americans.
When asked what factors helped to increase accessibility to medical and social services, all participants highlighted the assistance provided by community centers (Table 4). Local community centers were described as physical and social spaces from which participants were able to access support and seek community. First-generation participants shared that community centers offer helpful services including medical interpretation, assistance with filling out official documents, information about other community resources, and basic needs supplies. Additionally, community centers helped first-generation participants who faced technology barriers to access other social services through online portals and websites. Second-generation participants also noted that Southeast Asian Development Center provided critical access to food during the COVID-19 pandemic.
Participants also shared the interruption of services provided by community centers due to the pandemic affected the support they were able to receive in seeking out medical and social services, as well as impacted their sense of social connectedness. First-generation participants expressed frustration and stress as COVID-19 restrictions limited the ability to engage in their communities culturally and religiously, including access to spiritual services and their ability to visit their home countries.
Most participants agreed on the importance of wearing personal protective equipment (PPE), social distancing, and sheltering-in-place to minimize the risk of COVID-19 infection (Table 4). In addition, all participants shared concerns about visiting clinics or hospitals due to worry of increased exposure to COVID-19 in clinical settings. Although many participants shared their discomfort of wearing face coverings for extended durations and feelings of isolation and loneliness while sheltering-in-place, participants mentioned the importance of such precautions to keep themselves, their families, and their communities as safe as possible. Many first-generation participants highlighted the increased financial burden of purchasing PPE and cleaning supplies on limited, fixed incomes.
Most participants expressed satisfaction with the availability of testing sites, as well as vaccination sites when they were eligible to be vaccinated (Table 4). Many first-generation participants emphasized the convenience of community testing sites located in their neighborhoods. Some expressed frustrations of the lack of language access at COVID-19 testing and vaccination sites. Second-generation participants highlighted their role in helping elder family members locate testing and vaccination sites and making appointments through websites and mobile apps. The lack of information about COVID-19 testing and vaccines in participants’ native languages contributed to skepticism and hesitancy to getting tested or vaccinated. Despite the challenges of navigating COVID-19 testing and vaccination, almost all participants who were vaccinated expressed feeling more safe and less anxious about contracting severe COVID-19 disease. Participants’ perception of why others in their communities were not getting vaccinated include mistrust of the health care system, cultural or political beliefs, and fear of vaccine side effects.
In our unique study of the San Francisco Bay Area Southeast Asian American community’s experiences during the first phase of the COVID-19 pandemic (March 2020 to July 2021), we found deleterious effects of the pandemic on health care utilization. Our findings highlighted participants of the same generational status faced similar barriers to health care access and utilization compared to differences based on ethnicity (e.g. first-generation participants across ethnicities faced similar barriers and second-generation participants across ethnicities faced similar barriers). Furthermore, the fear of anti-Asian violence overshadowed and shaped the experiences of many participants. However, intergenerational support ameliorated the experiences of first-generation participants and community centers were vital to supporting the community during a tumultuous time. The experiences of Southeast Asian Americans need to be uplifted and recognized to improve the health outcomes of a historically overshadowed community. Generational differences in cultural, linguistic, and technological factors need to be considered when serving Southeast Asian Americans. The findings from the study are crucial to advancing health equity among Southeast Asian Americans and can be mapped to the Center for Disease Control and Prevention’s framework for ‘10 Essential Public Health Services’ (Figure 2).29
Figure 2. Adapted centers for disease control and prevention ‘10 essential public health services’ framework.29
Throughout the pandemic, the fear of anti-Asian violence permeated every aspect of life for many community members. The majority of first-generation Southeast Asian Americans resettled in the US as immigrants and refugees from genocide, war, persecution, and poor living conditions in Southeast Asian homelands and refugee camps.24 The heightened atmosphere of anti-Asian violence and xenophobia may resurface experiences of trauma and violence that the first-generation participants previously fled, intensifying fear of anti-Asian violence against themselves and their families. Many participants highlighted how their general fear of COVID-19 illness was further compounded by fear of anti-Asian violence leading them to limit public outings and to practice hypervigilance in public settings. This fear and anxiety contributed another barrier to accessing medical resources and prevented many from carrying out necessary day-to-day activities including exercise, running errands, and using public transportation. Given the history of war and trauma experienced by Southeast Asian Americans, further harm and distress to community members must be prevented by advocating for resources to promote community safety and healing, such as expanded access to mental health services and trauma-informed care.30 The expansion of culturally relevant mental health resources will allow community members to process trauma and minimize the perpetuation of intergenerational trauma onto younger generations.31 As carriers of past trauma, it is likely that the Southeast Asian American community may continue to be affected by the fear of anti-Asian violence, even after the COVID-19 pandemic era. As the United States moves forward from the COVID-19 pandemic, the public health infrastructure needs further assessment and to ‘investigate, diagnose, and address health hazards and root causes’ such as impacts of racism and discrimination on mental health outcomes.29
The majority of Cambodian, Laotian, and Vietnamese Americans fled war-torn homelands in the late twentieth century and resettled across the United States. Southeast Asian Americans have some of the lowest median household incomes and education attainment rates compared to other Asian American subgroups.32 At the beginning of the pandemic, there were large reductions in non-emergent health services as well as racial or ethnic and income disparities between users of in-person care and telemedicine when many health systems reduced services. The reduction and shift to telehealth during the pandemic limited health care access to those who could navigate telehealth visits, which typically required stable internet connection, English proficiency, and technology literacy, and often excluded many first-generation participants. While COVID-19 services such as testing and vaccination were eventually available in their communities, similar barriers posed to utilizing non-COVID-19 health services such as language and technology were still hindering Southeast Asian Americans from accessing the services without support. Telehealth options helped many participants access health services during the pandemic, but exacerbated barriers for others without the language or technological skills needed to utilize telehealth services.33 While technology can be imperative to addressing health disparities, technology must be intentionally developed to serve the needs of vulnerable communities. Without the support of second-generation family members and community centers, many first-generation participants would not have been able to utilize telehealth services, leading to health care access delays and worse health status.
Culturally relevant and linguistically accessible health services need to be prioritized throughout the entire process of health care utilization, especially during emergent times, to ensure that the most vulnerable populations can access quality health care. In terms of language access, all first-generation participants identified a language other than English as their primary language and had limited English proficiency. While studies examining disparities in health access among Asian Americans during the pandemic are limited, a federally qualified health center in Oakland, California, found that 49% of the 1,297 Asian American participants surveyed indicated that they could not find a place to get tested during the summer of 2020.25 One year later, partnerships with community-based organizations in the San Francisco Bay Area have made COVID-19 testing services more readily accessible for underserved communities, including linguistic access.34 Participants reported differences in the availability and quality of language interpretation services among Khmer, Lao, and Vietnamese language needs. Among the first-generation participants, Khmer and Lao-speaking participants were less likely to be able to read their native language script compared to Vietnamese participants, limiting the effectiveness of translated written language. The varied language access experiences of our first-generation participants highlight the need for expanded language access in non-medical settings and throughout the process of health care utilization (e.g. medical documents, patient portals), as well as more reliable, quality access to language interpretation in medical settings consistent with Title VI of the Civil Rights Act.35 Without ensuring culturally relevant and linguistically accessible services, limited English proficient patients will be hindered from receiving quality care. In order to expand assurance of health equity, language and technology barriers need to be considered to ‘expand equitable access’ to health services.29
Asian Americans are not a monolith and cannot be considered an aggregate. Therefore, community programs and interventions need to be tailored to the needs of each community. This suggests the value of community and community-oriented health among Southeast Asian Americans and the potential of pursuing community-led health interventions in advancing health for Southeast Asian Americans. Despite the uncertainty of the pandemic, fear of anti-Asian violence, and exacerbated barriers to health care access, many participants strived to maintain their health and continued to utilize health services as much as possible. There was a strong, reciprocal relationship of care and concern between generations regarding each generation’s health and safety, reflective of the interdependent, community-oriented values shared by many Southeast Asian Americans. Community and cultural centers have been and continue to be vital for providing basic resources and information to community members, especially for many first-generation community members. For many of these community members and their families, community centers provide key services, such as language interpretation, resource navigation, and the sharing of essential information, and intricately understand the needs of the communities they serve. The continued support and expansion of community-based organizations through increased funding and institutional support are pivotal to improving the health of underserved Southeast Asian American communities. In the process of advancing health equity, policy development must ‘strengthen, support, and mobilize communities and partnerships’ such as community-based organizations and the key roles they play in their communities.29
Our study revealed the lived experiences of Cambodian, Laotian, and Vietnamese participants and showcased on-going challenges that need to the addressed to improve health care access and ultimately health outcomes for these communities. While the COVID-19 pandemic certainly exacerbated longstanding health care access barriers, such as language access, the pivotal event also highlighted newer challenges, such as technology literacy, in our everchanging healthcare system.
Thematic saturation was achieved but not without study limitations. Firstly, the study was conducted in the San Francisco Bay Area and may not be generalizable to other Southeast Asian American communities.36 Secondly, the participants were primarily recruited through Southeast Asian American-serving community-based organizations in San Francisco, so participants in the study may be more likely to utilize community-based services and be more socially connected to their communities. Thirdly, the inherent on-going nature of the COVID-19 pandemic and spike in anti-Asian violence may have deterred risk-averse, vulnerable, or immunocompromised individuals from participating in the study. In addition, our community partners preferentially recruited participants who were vaccinated for COVID-19 and asymptomatic to minimize the risk of COVID-19 infections during study participation. This may have shifted the selection of participants to primarily include participants who were more likely to utilize health services and adhere to public health guidance.
This is the first study, to our knowledge, to investigate the impact of the COVID-19 pandemic on Cambodian, Laotian, and Vietnamese Americans across first-generation and second-generation participants. The study findings demonstrate the exacerbation of barriers to health care utilization, such as language and technology, under the circumstances of the pandemic and concurrent atmosphere of anti-Asian violence. Health care access barriers differ between first-generation and second-generation Southeast Asian Americans and tailoring social and health care services to generational needs could enhance health care utilization. Furthermore, structural and cultural changes are needed to eliminate racial discrimination and violence towards Asian Americans and promote physical and psychosocial safety. There needs to be continued expansion of culturally relevant, linguistically accessible, and trauma-informed health care services and increased funding and increased support of community-based organizations who are at the forefronts of Southeast Asian American communities.
We would like to acknowledge our community partners and respective community leaders affiliated with each organization for their support with language interpretation and participant recruitment and guidance in development and direction of this research project: Southeast Asian Development Center, Cambodian Community Development Inc., and the Lao Seri Association. We would also like to thank the Stanford Center for Asian Health Research and Education for their support, guidance, and encouragement to advance Asian health.
This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Stanford University Institutional Review Board (May 12, 2021, #60712). Informed consent was obtained from all individual participants included in the study and written informed consent was obtained from parents or guardians of participants who were under 18 years of age.
The data that support the findings of this study are available from the corresponding author, DC, upon reasonable request.