RADx-UP: Understanding 

the Factors Associated 

with Disparities in 

COVID-19 Morbidity and 

Mortality

MARCH 2024
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Table of Contents

Executive Summary .................................................................................................2

Establishment of the Program................................................................................2

Program Overview and Structure..........................................................................3

Data Collection and Sharing...................................................................................4

Funding Phases.........................................................................................................4

Program Accomplishments.....................................................................................8

Community Engagement.......................................................................................10

Impact and the Path Moving Forward ................................................................12

Conclusion...............................................................................................................13
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Executive Summary

The Rapid Acceleration of Diagnostics (RADx®)-Underserved Populations (UP) program was 

launched by the National Institutes of Health (NIH) in 2020 as part of the Rapid Acceleration of 

Diagnostics (RADx®) initiative. The overarching mission of RADx-UP has been to assess and 

expand SARS-CoV-2 (COVID-19) testing in the United States (U.S.) to promote protective 

strategies and reduce disparities in morbidity and mortality for racial and ethnic minoritized 

populations and other socially or medically vulnerable populations who have been known to be 

disproportionately affected by COVID-19. This includes populations most affected by health 

disparities, particularly persons identified as Black or African American, Hispanic or Latino, 

American Indian, Alaska Native, Hawaiian and Pacific Islander; those in nursing homes, jails, 

rural, or underserved urban areas; pregnant people; people with disabilities through the life 

course and people experiencing homelessness. 

Previous and ongoing projects supported by the RADx-UP program have been designed to 

rapidly respond to an evolving COVID-19 pandemic through coordinating the efforts of existing 

research infrastructures across the U.S. and its territories. Each of the independent RADx-UP 

research projects has been required to build and expand existing community partnerships to 

identify and collaboratively develop strategies to address the unique needs of underserved and 

vulnerable populations. The 142 awarded projects that have been funded through this program 

were conceived of and implemented as a consortium to build further collaborations, share 

research results with community partners and beyond, disseminate and implement results, and 

increase trust and inclusion in research under the leadership of a Coordination and Data 

Collection Center (CDCC). 

Establishment of the Program

Scientific leaders from NIH presented a framework to significantly increase the number, quality, 

and type of daily tests to detect SARS-CoV-2 and to help reduce inequities for underserved 

populations. Based on disparities in the testing landscape in 2020, an urgent need was identified 

for nationwide deployment of diagnostic tests that could be implemented in community and 
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home settings and to rapidly return results to all individuals. In response, NIH created the RADx 

initiative just five days after Congress provided a supplemental appropriation to the NIH Office 

of the Director as part of the Paycheck Protection Program and Health Care Enhancement Act of 

April 24, 2020. In 2021, funding support of the RADx initiative transitioned to the American 

Rescue Plan Act of 2021. As part of efforts to reduce the excess morbidity and mortality 

impacting specific populations disproportionately affected by COVID-19, NIH 

established RADx-UP, representing the largest investment in underserved communities in the 

history of NIH. 

Program Overview and Structure

Research project teams that have been supported by RADx-UP are grounded in academiccommunity collaborations. They have worked together to culturally and linguistically adapt 

research approaches and data collection instruments to identify and address disparities in 

infection rates, protective factors, health outcomes, and access to health care among underserved 

and vulnerable populations. While most RADx-UP research projects are focused on 

implementing and evaluating testing interventions, some focus on the social, ethical, and 

behavioral implications (SEBI) of testing. SEBI data identifies factors that create ethical 

dilemmas, behavioral conflicts, or have social implications that affects access and uptake of 

COVID-19 mitigation measures specific to certain groups. For example, some migrant workers

do not have access to health insurance or guaranteed income to support their families in the case 

of a positive COVID-19 test; thus, there may be hesitation to undergo testing to reduce the 

economic threat to the worker and to the family. In addition, the Safe Return to School 

Diagnostic Testing (R2S) component of RADx-UP has sought ways to understand strategies to 

facilitate the return to in-person learning for schools and districts serving underserved 

communities. The initiative has evaluated testing and mitigation intervention approaches for 

children and families, as well as faculty and staff members in public schools and has also 

explored vaccine hesitancy and uptake. 
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Data Collection and Sharing

To ensure comparability of data collected across all the projects in the RADx-UP consortium, the 

CDCC has worked with the funded research projects as well as NIH to identify and define a set 

of Common Data Elements (CDEs). The tier 1 CDEs are 169 items covering demographics, 

COVID-related behaviors and outcomes, risk behaviors, and selected social determinants of 

health. The collection and reporting of the NIH RADx-UP CDEs across this large set of 

community-engaged projects has presented a unique opportunity to facilitate cross-consortium 

analyses of research questions. Researchers can access curated and de-identified COVID-19 data 

through the NIH RADx Data Hub, a resource of RADx-generated data that can help researchers 

better understand the impact of the pandemic, including the outcomes, disparities, and potential 

solutions. 

Within the RADx initiative, 11 funded research projects have focused on understanding and 

addressing COVID-19 disparities within American Indian and Alaska Native (AI/AN) 

communities. Important aspects of these studies have included ensuring responsible data sharing 

and access with respect for Tribal sovereignty and appropriate governance to maximize 

partnerships, participation, and community benefit. To address unique cultural, governance, and 

sovereignty needs of the AI/AN communities engaged in the RADx initiative, NIH launched 

the RADx Tribal Data Repository (TDR). TDR is designed for sovereignty-based governance of 

AI/AN data collected through RADx projects; this will enable Tribal controlled sharing and use 

of data to better understand and address the impact of COVID-19 and other health disparities.

Funding Phases

The RADx–UP program has been implemented in four phases to permit a flexible response to 

the rapidly evolving pandemic and impact on communities across the nation. Phase I projects 

have supplemented pre-existing large-scale networks, consortia, centers, and individual research 

projects to examine SARS-CoV-2 infection patterns. Projects have utilized community-engaged 

research principles to investigate a variety of COVID-19 diagnostic testing methods that received 

Food and Drug Administration (FDA) Emergency Use Authorization to increase access, use, and 
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effectiveness of testing methods. The SEBI research has sought to identify, analyze, and address 

the social, ethical, and behavioral factors likely to influence access and uptake of COVID-19 

testing in underserved and vulnerable populations. Phase II projects have advanced the scientific 

mission of the program and have addressed new developments in the landscape of COVID-19 

testing and diagnostic approaches as well as vaccine confidence, hesitancy, and uptake. Phase III 

projects have supported the evaluation of rapid testing interventions to prevent and control 

COVID-19 transmission and advance community driven research. Phase IV projects leverage 

existing RADx-UP data to gain novel insights through cross-project analyses and support 

dissemination and implementation (D&I) research focused on increasing access to and uptake of 

COVID-19 testing interventions to reduce COVID-19 disparities and promote health equity.

The figure below displays the objectives of the four RADx-Up program phases and the months 

in which these projects were initially awarded funding (i.e., these dates reflect release of awards 

by phase and not total duration of project).

Phase I. Understanding COVID-19 Testing Patterns by Focusing on NIH Funded Projects 

with Established Community Engaged Research Infrastructures and Partnerships 

The initial phase of the RADx-UP program has focused on mobilizing research teams with 

established research infrastructures and community-engaged partnerships. These teams have 

been funded to study COVID-19 testing patterns and to implement strategies or interventions 

with the potential to rapidly increase reach, access, acceptance, and uptake of COVID-19 

diagnostics (only those that received EUA) among underserved and other socially or medically 

vulnerable populations.
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Phase I projects were awarded in September through November of 2020 with awards to 69 

projects and the establishment of the RADx-UP CDCC, a central leadership and support team 

that assisted the NIH and RADx-UP projects as they served their communities. These project 

awards have been administered by 15 NIH institutes at 55 research institutions within 34 states, 

the District of Columbia, and Puerto Rico.

Data collected by each RADx-UP project, with special consideration for Tribal Nation practices 

and policies concerning data sovereignty, have been harmonized, de-identified and uploaded 

quarterly to the RADx-UP CDCC then transferred to the RADx Data Hub. To date more than 55 

million responses to the CDEs collected from more than 400,000 participants have been 

uploaded to the Data Hub.

Phase II. New Advances in COVID-19 Testing 

Phase II has focused on the integration of new technological advances in COVID-19 testing, 

including point-of-care or at-home rapid testing. In conjunction with the expansion of the scope 

and reach of testing interventions, these projects have sought to increase access and uptake of 

COVID-19 testing among underserved and vulnerable populations. RADx-UP has been able to 

focus on understanding and addressing the social, ethical, and behavioral implications on the 

testing interventions in these populations during this phase.

This new phase also has added school-based research to address high-priority topics related to 

the use of COVID-19 testing as part of a strategy to facilitate the safe return to school for 

students and families, as well as faculty and staff members.

Phase II began with 16 Return-to-School awards in April and June 2021 followed by 42 

additional awards related to advances in COVID-19 testing in community settings in November 

2021, for a total of 58 new projects. These projects have been administered by 11 NIH institutes 

at 58 research institutions within 28 states. During this phase of the program, COVID-19

vaccination uptake research became a secondary focus and RADx-UP began to collaborate with 
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the NIH Community Engagement Alliance1(CEAL) projects through 11 administrative 

supplements for Phase I projects to further study testing and vaccine hesitancy and uptake.

Phase III. Rapid Testing 

New awards in Phase III have primarily focused on community-engaged research to implement 

and evaluate SARS-CoV-2 rapid testing and testing in schools, referred to as Safe-in-School. 

Projects have also continued SEBI research to gain insights to reduce barriers in COVID-19 

testing and the associated COVID-19 disparities. Other projects awarded in this phase evaluated 

the rapid COVID-19 testing, typically administered outside of healthcare settings, to prevent and 

control COVID-19 transmission as well as the partnership-driven research for the 

implementation and evaluation of rapid testing for the reduction of COVID-19 disparities in 

underserved and vulnerable populations. 

In October 2022, 10 projects received Phase III awards and have been administered by three NIH 

institutes at nine research institutions within eight states. 

Phase IV. Cross-site Analysis of Existing RADx-UP Data, and New Dissemination and 

Implementation Research

Phase IV of the program has focused on two areas: cross-site analysis of existing RADx-UP data 

to gain novel insights and projects focused on dissemination and implementation of effective 

COVID-19 testing interventions in underserved populations. Four cross-site analysis projects 

were awarded in September 2023. These projects have been administered by the National 

Institute on Minority Health and Health Disparities at four research institutions in four states. 

Dissemination and implementation research projects will explore how evidence-based RADx-UP 

practices, interventions, and policies translate effectively for use in real-world settings. 

Additional dissemination and implementation research awards are expected in June 2024.

Through these phases, the RADx-UP program has identified several key findings, including:

1 Formerly known as the Community Engagement Alliance Against COVID-19 Disparities. 
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• Community-engaged and directed research has been integral to implementing testing and 

mitigation strategies, and has required time and attention to build trust, adequate 

compensation for community collaborators, and investment of full partnership among 

researchers, community participants, and NIH scientific staff. 

• There have been racial, ethnic, and socioeconomic status disparities in testing motivation

and vaccine access and uptake, although these disparities have not been uniform across 

the different racial and ethnic groups.

• Developing public health strategies (such as health education), providing trusted sources 

of information, and addressing barriers have been positively impacting reliance on 

COVID-19 testing and vaccination.

• Racial and ethnic minority groups experience elevated challenges related to social 

determinants of health (e.g., limited English proficiency, access to quality healthcare, 

transportation and geographical barriers) that may impact access to COVID-19 testing

and managing recommendations following a positive COVID-19 test.

• Mitigation strategies have been effective at reducing SARS-CoV-2 virus transmission in 

schools.

Program Accomplishments 

The RADx-UP program has played a critical role in advancing the overarching RADx goal that 

all persons living in the U.S. have access to COVID-19 testing. Research teams and community 

leaders across the country have access to research data to identify and develop effective 

strategies for reducing disparities and addressing community needs. 

As of December 2023, the RADx-UP program has reflected on the following accomplishments 

and highlights:

• NIH published 16 funding opportunities and has awarded 142 projects, including the 

RADx-UP Coordination and Data Collection Center (CDCC).

• More than 404,000 participants have enrolled in RADx-UP research studies.
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o Participation has included substantial representation from underserved 

communities disproportionately affected by COVID-19 and often 

underrepresented in research, including AI/AN, Hawaiian, and Pacific Islander 

groups.

o Socioeconomically disadvantaged persons and members from 18 additional 

underserved groups that have been known to experience barriers to accessing 

health care services, to have had inadequate healthcare coverage, or to have been 

vulnerable to COVID-19 due to specific medical conditions, social determinants, 

or living situations have participated in the research.

o Names, contact information, and basic socio-demographic information for all 

participants who agreed to both share their identifiers with the CDCC and to be 

re-contacted for future research when they enrolled in RADx-UP studies have 

become available in the RADx-UP Re-contact Registry.

• Project sites have been supported in all 50 States, the District of Columbia, and the U.S.

territories, including Puerto Rico, the U.S. Virgin Islands, Guam, and American Samoa. 

Nine distinct research settings included community health centers, in-home, underserved 

urban and rural communities, school, public housing, nursing home or long-term care 

facilities, and prison or correctional facility.

• RADx-UP project teams have distributed and/or conducted millions of COVID-19 tests 

and transferred CDEs data collected from participants reporting on more than 447,000 

tests. 

• As of December 2023, 1,384 RADx-UP unique research project authors have published 

more than 270 research articles in 112 academic journals. These publications include two 

special supplements to Pediatrics and a special issue of the American Journal of Public 

Health (November 2022). There will also be a second AJPH supplement to be released in 

spring 2024.

• Of 142 awarded projects, 101 projects have completed CDE data collection and are in or 

entering the final stages of depositing data with the RADx-UP CDCC and transfer of the 

data to the RADx Data Hub.
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Community Engagement

Engagement with community partners has been critical to understanding and integrating 

strategies to mitigate health inequities. RADx-UP has strengthened existing relationships 

between academic researchers and their community partners which facilitated the rapid 

mobilization needed to implement interventions, enhance acceptance, and communicate the 

importance of COVID-19 testing. These partnerships have also strengthened community 

infrastructure to be better prepared for future public health emergencies. 

Two examples of projects, among many similar successes, are described below: 

• Led by the University of Oregon, the Oregon Saludable: Juntos Podemos project has 

focused its efforts on increasing COVID-19 testing and other COVID-19 transmission 

prevention behaviors among Latino community members across 11 counties in Oregon. 

Using promotores de salud, an individual level intervention, the researchers have 

determined that culturally informed outreach can increase community engagement and 

participation. The promotores, bilingual and bicultural health outreach workers, has 

successfully delivered culturally tailored health education to the Latino communities and 

have increased COVID-19 testing by nearly four times per testing event compared to 

sites with outreach as usual. Further, the researchers have determined that those who 

were vaccine hesitant had concerns about side effects and had not been given sufficient 

information about vaccine efficacy. This has provided a better understanding of how to 

reduce disparities in health care among these communities. 

• The RADx-UP Safe Return to School Diagnostic Testing Initiative has aimed to build the 

evidence base for safely returning students, teachers, and staff members to in-person 

school settings in areas with underserved and vulnerable populations. Researchers have 

sought to understand the motivators and barriers to testing from different perspectives to 

increase participation in school-based testing programs. Key motivators of COVID-19 

testing in school have included the convenience of testing in schools as well as the desire 

to keep oneself and others safe from COVID-19; however, some have been concerned 

about the implications of receiving a positive test result. By establishing COVID-19 
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testing protocols for schools in vulnerable communities, these projects have helped 

inform policy and decision-makers on the best strategies to support students, teachers, 

and staff members in a safe return to school during the COVID-19 pandemic and which 

can be applied to future pandemics and public health emergencies. 

o With a special issue published in the journal Pediatrics, studies conducted by the 

ABC Science Collaborative concluded that offering in-school testing increased 

the testing of close contacts of positive students and allowed for shortened 

quarantine durations; nursing staff were critical to the success; and where 

resources were limited, testing was more difficult.

In addition to supporting individual projects, the RADx-UP community of practice has produced 

lessons learned and other resources to aid in community engagement.

• The annual RADx-UP Scientific Meeting featured the data results and lessons learned 

from dozens of RADx-UP projects. In addition to academic researchers, community 

partners presented findings and valuable insights, highlighting RADx-UP’s dedication to 

authentic, sustainable community partnership.

• The bilingual RADx-UP Community Health Worker Symposium, in English and 

Spanish, highlighted the essential role of Community Health Workers (CHWs) in 

promoting health equity. Presenters included CHWs who shared their experiences in the 

field and suggestions for improvements.

• The Engagement Resource Library contains some 300 tools for researchers and 

communities on areas such as community engagement best practices, research study 

recruitment and participation, health equity, and more.

• The figure below provides a graphic representation of the many resources developed by 

the projects in the RADx-UP Community of Practice that are now publicly available for 

adaptation in use in other contexts. 
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Impact and the Path Moving Forward

The RADx-UP program has brought together academic researchers and community members 

from across the U.S. to develop innovative approaches to expanding COVID-19 testing for 

underserved and vulnerable populations. RADx-UP has gathered insights about promising testing 

and vaccination approaches that can translate research into sustainable programs, practices, and 

policies. 

Testing and vaccine implementation in underserved and vulnerable populations should take the 

following into account:

• The importance of identifying and implementing CDEs early and carefully:

o Community partners must be active participants and co-creators; this requires 

bidirectionality in communication and full and equal collaboration

o Language adaptations need to go beyond word-for-word translation because

cultural considerations are critical to inclusivity as well as reliability and validity 

of research results 
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o Scientific and community benefits are possible by measuring standard 

demographic factors, social determinants of health, and COVID-19-related 

variables using standardized questions (i.e., NIH RADx-UP CDEs) that permit 

cross-site analysis and consortium-level findings

• Privacy, transparency, security, and data sovereignty are critical to building community 

trust in the research process and with researchers 

• Community engagement is most effective when given appropriate time and attention, 

adequate compensation for community collaborators, and full partnership 

among researchers, community participants, and NIH scientific staff

• Developing culturally appropriate testing and vaccination strategies requires knowledge 

of the social context and lived experience within each community

The outcomes from the RADx-UP program have provided valuable information and resources to 

reduce disparities for those who are disproportionally affected by, have the highest infection 

rates, and are at risk for complications or poor outcomes from the COVID-19 pandemic. 

Conclusion

In summary, RADx-UP has provided a timely, responsive mechanism to support innovative 

research projects seeking to understand testing patterns of COVID-19 and the implementation of 

strategies to rapidly increase reach and access to approved diagnostics among populations 

experiencing health disparities or are otherwise underserved. The impact of RADx-UP 

community engagement has allowed for a wide breadth of populations to connect with COVID19 mitigation resources. 

RADx-UP can continue to inform efforts to alleviate barriers to testing for the most vulnerable 

populations and reduce health disparities by:

• Fostering stronger community collaborations with academic researchers and extending 

community-directed research through published research results including crossconsortium analyses of aggregated RADx-UP data, findings shared at the 2023 Equity 

Evidence Academy, and additional dissemination activities.
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• Informing public health policy decisions at local, state, and federal levels and 

implementing effective strategies for reducing disparities in future pandemics. Examples 

of RADx-UP outputs to support this include the Health Equity Framework, the 

Opportunities to Enhance Health Equity by Integrating Community Health Workers into 

Payment and Care Delivery Reforms.

• Evaluating intervention approaches across cultural groups and environments and 

assessing the impacts on reducing health disparities.

• Understanding the mental health effects and substance misuse associated with COVID19, social isolation, and the overall impacts on health and health care access for nonrespiratory acute illness due to fear of exposure to COVID-19 in healthcare facilities.

• Understanding the effects of health care on persons with chronic medical conditions

requiring ongoing monitoring.

• Evaluating the impact of forced social isolation at all ages and environments, including 

students required to attend remote education. 

• Building and maintaining important relationships to allow lasting impact on underserved 

and vulnerable populations. 

The knowledge gained through the RADx-UP program, and the strategies that the communityengaged research teams developed throughout all phases of the program, can be used to address 

future public health crises in vulnerable communities. This program has an expansive footprint 

across the U.S. and its affiliated territories that reaches underserved and vulnerable populations 

to mitigate the health disparities of COVID-19. It represents only the beginning of the impact 

that the NIH and its research partners can have on the health of the nation.