Addressing Underrepresentation of Minorities in Research: Strategies for Inclusion

Research findings only carry scientific weight when the populations studied reflect the populations affected by the condition or intervention in question. When minority groups are underrepresented in studies, the resulting data may not apply to them, treatment decisions may be based on incomplete evidence, and health disparities can widen. This article provides researchers, students, and life-science professionals with practical strategies to improve representation of minority groups in research, from recruitment planning through data reporting. The focus is on actionable steps that can be embedded into study design, participant outreach, data collection, and publication practices.

The Scope of Underrepresentation in Research

Underrepresentation of minorities in research is a documented problem across multiple fields. A review of ecological momentary assessment studies on co-use of nicotine, alcohol, and cannabis found that most research relied on cross-sectional or sparse longitudinal observations, with variations by minority status rarely examined. The authors noted that co-use has become prevalent among racial and ethnic minority individuals who exhibit distinct co-use patterns and related outcomes, yet the research base does not adequately capture these differences. The review called for more research to capture time-intensive data on experiences to contextualize co-use among racial and ethnic minority groups with greater diversity in race and ethnicity. This example illustrates a broader pattern where study designs and recruitment approaches fail to include the very populations most affected by the health behaviors under investigation.

Similar patterns appear in neurodevelopmental conditions research. A review in Nature Reviews Neurology described how sex and gender are important contributors to biological and behavioral variability in neurodevelopmental conditions, yet methodological caveats such as frequent conflation of sex and gender constructs, inappropriate measurement of these constructs, and underrepresentation of specific demographic groups limit the translational potential of research. The review specifically identified female and gender minority individuals and people with intellectual disabilities as groups that are underrepresented. When these groups are excluded, findings about autism, attention-deficit/hyperactivity disorder, and other neurodevelopmental conditions may not generalize to them.

The problem extends to precision medicine initiatives. An analysis of the All of Us Research Program cohort from 2018 to 2023 found that blind and deaf participants were considerably underrepresented, especially among working-age adults younger than 65 years, as well as Asian and multi-racial participants. The analysis showed compounded underrepresentation at the intersection of multiple marginalized identities, most substantively for working-age blind participants identifying as Black or African American female with education levels lower than high school. The authors raised concerns about the generalizability of findings in studies that use these data and limited benefits for the already underserved blind and deaf populations.

Clinical trials show the same gaps. A bibliographic record in Gastroenterology documented underrepresentation of minorities and underreporting of race and ethnicity in Crohn's disease clinical trials. When race and ethnicity data are not even reported, it becomes impossible to assess whether trial results apply across populations. A survey of South Asian and African communities in Glasgow found considerable recognition among respondents that treatment needs to be ethnicity-specific and that current cardiovascular disease treatment guidelines were not tailored for different ethnicities. The survey, co-developed with community representatives, achieved a response rate of 337 out of 500 distributed questionnaires, with most respondents not born in the UK and in the 35 to 53 year age group.

Why Representation Matters for Research Validity

The scientific case for inclusion rests on the principle that health-related conditions often differ qualitatively or quantitatively between individuals of different birth-assigned sexes, gender identities, and gendered experiences. The Nature Reviews Neurology article emphasized that studying the moderating and mediating effects of sex-related and gender-related factors on impairment, disability, wellbeing, and health is of paramount importance, especially for neurodivergent individuals who are diagnosed with neurodevelopmental conditions with uneven sex and gender distributions. When research samples do not include these groups, the mechanisms through which sex and gender effects operate remain unexplored.

Ethnic differences in treatment response and outcomes provide another compelling reason for inclusion. The Glasgow hypertension survey noted that hypertension is the biggest contributor to global cardiovascular burden with evidence for ethnic differences in treatment response and outcomes. If clinical trials for hypertension medications enroll predominantly White participants, clinicians lack evidence about whether those medications work equally well in South Asian and African patients. The survey respondents recognized this gap, with nearly half of South Asian respondents and 45 percent of African respondents agreeing that treatment needs to be ethnicity-specific.

The consequences of underrepresentation extend beyond clinical care. A commentary in Ethnicity & Disease noted that Asian Americans are the fastest growing racial and ethnic minority group in the United States and have unique, heterogeneous health status and outcomes across a range of conditions between disaggregated Asian subgroups. Yet clinical and epidemiologic research lags considerably in adequately and appropriately representing Asian Americans. Too often, Asian American participants and populations are inappropriately aggregated into a single race category in research, masking important differences between ethnic subgroups. This aggregation problem means that even when Asian Americans are included, the data may be too coarse to reveal subgroup-specific patterns.

At a Glance: Key Strategies for Inclusive Research

Core Principles for Inclusive Research Design

Set Inclusion Criteria Based on Disease Burden

Inclusion targets should be grounded in the epidemiology of the condition being studied. If a condition disproportionately affects certain minority groups, the study sample should reflect that distribution. The Glasgow hypertension survey demonstrated this principle by focusing on South Asian and African communities because of evidence for ethnic differences in treatment response and outcomes. Researchers should review the literature on disease prevalence, severity, and outcomes across demographic groups before finalizing eligibility criteria.

Eligibility criteria themselves can create barriers to inclusion. Restrictive criteria that exclude participants based on comorbidities, language proficiency, or transportation access can systematically exclude minority groups. The qualitative study of healthcare professionals' perspectives on cancer clinical trial participation among Arabic-speaking cancer patients in Australia identified restrictive trial eligibility criteria as a structural barrier. Researchers should examine each eligibility criterion and ask whether it is scientifically necessary or whether it reflects convenience or tradition.

Engage Communities Before Designing the Study

Community engagement should occur during study planning, not after recruitment begins. The Glasgow survey was co-developed with representatives from South Asian and African patients and community members, which helped ensure that the survey questions were relevant and understandable. This approach also built trust between the research team and the communities being studied.

The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals identified limited consultation time, lack of translated study materials, and lack of workforce diversity as structural barriers to trial participation. These barriers can be addressed through community engagement that identifies specific needs, such as translated consent forms, interpreter services, and longer consultation slots for participants who need additional explanation.

Address Mistrust Through Transparent Practices

Mistrust toward researchers and research institutions is a documented barrier to participation. The EClinicalMedicine article on ethnic minority and migrant underrepresentation in Covid-19 research identified fear, mistrust, and access barriers as factors underlying disparities in research participation. The article noted that some migrant groups' concerns around the Covid-19 vaccine were due to their lack of inclusion in the clinical trials, highlighting an urgent need to understand and address the reasons underlying these disparities.

Transparent practices can help address mistrust. Researchers should clearly explain the purpose of the study, how data will be used, who will have access to the data, and what safeguards protect participant privacy. Community partners can help researchers communicate this information in ways that resonate with specific cultural contexts. The Research Data Framework from the National Institute of Standards and Technology provides a structure for thinking about data management practices that support transparency and reproducibility.

Practical Workflow for Inclusive Recruitment

Step 1: Assess the Current Evidence Base

Before designing a new study, researchers should review existing literature to understand what is known about the condition across different demographic groups. The PubMed database maintained by the National Library of Medicine and the broader NCBI Literature Resources can help researchers identify gaps in the evidence base. The EQUATOR Network provides access to reporting guidelines that can help researchers plan studies that will produce complete and transparent reports.

The review of ecological momentary assessment studies on substance co-use illustrates how a literature review can identify representation gaps. The authors searched for studies published from 2008 to 2023 involving racial and ethnic minority individuals and found that variations by minority status were rarely examined. This type of gap analysis should inform the design of new studies.

Step 2: Set Representation Targets

Representation targets should be specific, measurable, and tied to the research question. For example, if a study aims to understand hypertension management in South Asian and African communities, the recruitment plan should specify the number of participants needed from each community to detect clinically meaningful differences. The Glasgow survey achieved a response rate of 67.4 percent with 242 South Asian and 56 African respondents, demonstrating that targeted recruitment at community venues can yield adequate samples.

Targets should also address intersectionality. The All of Us Research Program analysis found compounded underrepresentation at the intersection of multiple marginalized identities, such as racial or ethnic minority group, female sex, low education, and low income. Researchers should consider whether their recruitment strategies will reach participants who hold multiple marginalized identities.

Step 3: Develop Culturally Appropriate Materials

Study materials, including consent forms, questionnaires, and recruitment advertisements, should be developed with input from community representatives. The Glasgow survey was co-developed with representatives from South Asian and African patients and community members, which helped ensure that the survey was understandable and acceptable.

The qualitative study of Arabic-speaking cancer patients in Australia found that lack of translated study materials was a structural barrier to participation. Healthcare professionals in that study advocated for translated materials, booking longer consults, and engaging interpreters to enable trial participation. Researchers should budget for translation and interpretation services as part of study planning.

Step 4: Recruit Through Trusted Channels

Recruitment through community venues and trusted organizations can improve participation. The Glasgow survey was distributed at public engagement events at venues that were frequently visited by South Asian and African communities. This approach reached adults aged over 18 years of South Asian or African ancestry and achieved a response rate of 67.4 percent.

The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals recruited participants via professional networks and social media using snowball sampling. This approach leveraged existing relationships and trust networks to reach participants who might not respond to traditional recruitment methods.

Step 5: Monitor Recruitment Progress

Recruitment should be monitored continuously to identify underrepresentation early. Researchers should track demographic characteristics of enrolled participants against representation targets and adjust recruitment strategies if targets are not being met. The Experimental Design Assistant from NC3Rs can help researchers plan experiments that account for biological variables such as sex, which is relevant for studies involving animal models that inform human research.

Data Collection and Measurement Considerations

Collect Disaggregated Demographic Data

The commentary on Asian American representation in research emphasized that aggregating diverse subgroups into a single race category masks important differences. Researchers should collect demographic data at the most granular level feasible, allowing for analysis of subgroup differences. For example, instead of a single "Asian" category, researchers might collect data on specific ethnic origins such as Chinese, Filipino, Indian, Vietnamese, or Korean.

The Nature Reviews Neurology article on sex and gender in neurodevelopmental conditions identified frequent conflation of sex and gender constructs and inappropriate measurement of these constructs as methodological caveats. Researchers should distinguish between sex assigned at birth and gender identity, and should use validated measures for each construct. The article on sex-specific neurocognitive impairment in Neurologic Clinics also discussed issues in assessment, including the use of gender and sex-specific normative data.

Use Validated and Adapted Instruments

Measurement instruments developed and validated in one population may not perform the same way in another population. Researchers should assess whether existing instruments have been validated for the populations they plan to study, and should adapt instruments when necessary. The Glasgow survey was co-developed with community representatives to ensure that questions about hypertension awareness and knowledge were relevant and understandable for South Asian and African communities.

The review of ecological momentary assessment studies on substance co-use noted that most studies relied on cross-sectional or sparse longitudinal observations. Ecological momentary assessment methods can capture time-intensive data on experiences, but these methods may place greater burden on participants. Researchers should consider whether the data collection method is feasible and acceptable for the populations they aim to include.

Address Language and Literacy Barriers

Language barriers can exclude participants who are not proficient in the dominant language of the research setting. The qualitative study of Arabic-speaking cancer patients in Australia found that English-language proficiency was a central barrier, with structural barriers including limited consultation time, restrictive trial eligibility criteria, lack of translated study materials, and lack of workforce diversity. Healthcare professionals in that study reported that language discourse reduced their confidence in patient understanding of trial information and consequently the informed consent procedure.

Researchers should plan for translation and interpretation services, and should ensure that study staff are trained to work with interpreters. The EClinicalMedicine article on ethnic minority and migrant underrepresentation in Covid-19 research noted that participant-related factors may include language and cultural barriers, and mistrust toward researchers and research institutions.

Records and Measurements for Inclusive Research

Track Demographic Data From the Start

Demographic data should be collected from all participants at enrollment, not added as an afterthought. Researchers should record race, ethnicity, sex, gender identity, age, education, income, and other relevant demographic variables. The All of Us Research Program analysis used electronic health records and compared participant demographics with national estimates from the Centers for Disease Control and Prevention. This type of comparison can help researchers assess whether their sample is representative.

Document Recruitment and Retention Activities

Detailed records of recruitment activities can help researchers understand which strategies are effective and which are not. Researchers should document where recruitment materials were distributed, which community organizations were engaged, how many potential participants were contacted, and how many enrolled. The Glasgow survey documented that 337 questionnaires were returned out of 500 distributed, with 39 excluded because of incompletion, yielding a response rate of 67.4 percent.

Measure Retention Separately From Recruitment

Underrepresentation can occur at the recruitment stage or at the retention stage. Researchers should track retention rates by demographic group to identify whether certain groups are more likely to drop out. The longitudinal observational study of Japanese older adults with mild cognitive impairment classified participants into continuous and non-continuous social participation groups based on participation at four time points over 18 months. This type of longitudinal tracking can reveal retention patterns that cross-sectional studies miss.

Common Failure Patterns in Inclusive Research

Failure to Report Demographic Data

The Crohn's disease clinical trials analysis documented underreporting of race and ethnicity. When demographic data are not reported, readers cannot assess whether study findings apply to their populations. Researchers should report demographic characteristics of enrolled participants in all publications, and should report the demographic characteristics of eligible but non-enrolled individuals when possible.

Failure to Disaggregate Data

Aggregating diverse subgroups into broad categories can mask important differences. The commentary on Asian American representation noted that aggregating Asian American participants into a single race category masks important differences between ethnic subgroups. Researchers should plan analyses that examine subgroup differences when sample sizes permit.

Failure to Consider Intersectionality

The All of Us Research Program analysis found compounded underrepresentation at the intersection of multiple marginalized identities. Researchers who focus on a single demographic dimension, such as race or sex, may miss patterns that emerge at the intersection of multiple dimensions. The article on intersectionality and underrepresentation among health care workforce, focusing on Arab physicians in Israel, illustrates how multiple identity dimensions interact to shape representation.

Failure to Engage Communities

Research designed without community input may fail to address the concerns and priorities of the populations being studied. The Glasgow survey was co-developed with community representatives, which helped ensure that the survey was relevant and acceptable. The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals became enablers to trial participation by advocating for translated materials, booking longer consults, and engaging interpreters.

Failure to Address Structural Barriers

Structural barriers such as limited consultation time, restrictive eligibility criteria, and lack of workforce diversity can systematically exclude minority groups. The qualitative study of Arabic-speaking cancer patients in Australia identified these barriers as structural, meaning they are embedded in how research is organized instead of in individual participant characteristics. Researchers should examine their own study procedures for structural barriers that could be modified.

Limitations and Tradeoffs in Inclusive Research

Sample Size and Statistical Power

Including diverse populations may require larger sample sizes to achieve adequate statistical power for subgroup analyses. Researchers should consider whether their study is powered to detect differences between demographic subgroups, and should be transparent about the limitations of underpowered subgroup analyses. The Glasgow survey included 242 South Asian and 56 African respondents, which may have limited the ability to detect differences between these groups.

Measurement Burden

Some data collection methods, such as ecological momentary assessment, place significant burden on participants. The review of EMA studies on substance co-use noted that most studies relied on cross-sectional or sparse longitudinal observations, possibly because of the burden of intensive data collection. Researchers should consider whether the data collection method is feasible and acceptable for the populations they aim to include.

Generalizability Versus Precision

There is a tradeoff between generalizability and precision in research design. A study that includes a diverse sample may produce findings that are more generalizable but less precise for any specific subgroup. Conversely, a study focused on a single subgroup may produce precise findings that do not generalize to other populations. Researchers should be explicit about which goal they are prioritizing and why.

Time and Resource Constraints

Community engagement, translation services, and targeted recruitment require additional time and resources. The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals advocated for booking longer consults and engaging interpreters, which requires additional clinical time. Researchers should budget for these activities in grant proposals and study plans.

Safety and Regulatory Context

Informed Consent and Language Access

Informed consent procedures must be accessible to all participants. The qualitative study of Arabic-speaking cancer patients in Australia found that language discourse reduced healthcare professionals' confidence in patient understanding of trial information and consequently the informed consent procedure. Researchers should ensure that consent materials are available in languages spoken by potential participants and that interpreters are available during the consent process.

Data Privacy and Confidentiality

Participants from minority groups may have heightened concerns about data privacy and confidentiality. The EClinicalMedicine article on ethnic minority and migrant underrepresentation in Covid-19 research identified mistrust toward researchers and research institutions as a barrier to participation. Researchers should clearly explain data protection measures and should consider whether their data management practices align with frameworks such as the Research Data Framework from the National Institute of Standards and Technology.

Regulatory Requirements

Research involving human participants is subject to regulatory requirements that vary by jurisdiction. Researchers should be aware of the specific requirements in their setting, including requirements related to informed consent, data protection, and reporting of demographic data. The EQUATOR Network provides access to reporting guidelines that can help researchers meet reporting standards.

Professional Escalation Criteria

Researchers should escalate concerns about underrepresentation when certain conditions are present. Escalation may involve consulting with institutional review boards, research ethics committees, community advisory boards, or regulatory authorities.

Escalate When Representation Gaps Threaten Study Validity

If recruitment data show that a study is systematically excluding a population that is disproportionately affected by the condition under study, researchers should escalate the concern. The All of Us Research Program analysis raised concerns about the generalizability of findings in studies that use these data and limited benefits for the already underserved blind and deaf populations. Researchers should consider whether the study should be paused or modified to address representation gaps.

Escalate When Community Concerns Are Not Being Addressed

If community partners raise concerns that are not being addressed by the research team, researchers should escalate those concerns to appropriate oversight bodies. The Glasgow survey found that respondents recognized that treatment needs to be ethnicity-specific and that current cardiovascular disease treatment guidelines were not tailored for different ethnicities. These types of community concerns should inform study design and should be escalated if they are being ignored.

Escalate When Reporting Standards Are Not Met

If publications from a study do not report demographic data, researchers should escalate the concern to journal editors or funders. The Crohn's disease clinical trials analysis documented underreporting of race and ethnicity, which limits the ability to assess generalizability. The EQUATOR Network provides reporting guidelines that can help researchers and reviewers assess whether demographic data have been adequately reported.

Frequently Asked Questions

Why are minority groups underrepresented in research?

Underrepresentation results from a combination of personal and structural factors. The EClinicalMedicine article on ethnic minority and migrant underrepresentation in Covid-19 research noted that socio-political factors may include social deprivation limiting access to health services, and subsequently, participation in and awareness of health research. Participant-related factors may include language and cultural barriers, and mistrust toward researchers and research institutions. Structural barriers identified in the qualitative study of Arabic-speaking cancer patients in Australia included limited consultation time, restrictive trial eligibility criteria, lack of translated study materials, and lack of workforce diversity.

How can researchers build trust with minority communities?

Researchers can build trust by engaging communities before designing the study, co-developing study materials with community representatives, recruiting through trusted channels, and being transparent about data use and privacy protections. The Glasgow survey was co-developed with representatives from South Asian and African patients and community members, which helped ensure that the survey was relevant and acceptable. The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals became enablers to trial participation by advocating for translated materials, booking longer consults, and engaging interpreters.

What demographic data should be collected in research studies?

Researchers should collect disaggregated data on race, ethnicity, sex, gender identity, age, education, income, and other relevant demographic variables. The commentary on Asian American representation emphasized that aggregating diverse subgroups into a single race category masks important differences between ethnic subgroups. The Nature Reviews Neurology article on sex and gender in neurodevelopmental conditions identified frequent conflation of sex and gender constructs and inappropriate measurement of these constructs as methodological caveats.

How can researchers address language barriers in research participation?

Researchers can address language barriers by providing translated study materials, engaging interpreters, and booking longer consultation times for participants who need additional explanation. The qualitative study of Arabic-speaking cancer patients in Australia found that healthcare professionals advocated for translated materials, booking longer consults, and engaging interpreters to enable trial participation. The study also identified lack of translated study materials as a structural barrier.

What is intersectionality and why does it matter in research?

Intersectionality refers to the ways that multiple marginalized identities interact to shape experiences and outcomes. The All of Us Research Program analysis found compounded underrepresentation at the intersection of multiple marginalized identities, such as racial or ethnic minority group, female sex, low education, and low income. The article on intersectionality and underrepresentation among health care workforce, focusing on Arab physicians in Israel, illustrates how multiple identity dimensions interact to shape representation.

How should researchers report demographic data in publications?

Researchers should report demographic characteristics of enrolled participants in all publications, and should report the demographic characteristics of eligible but non-enrolled individuals when possible. The Crohn's disease clinical trials analysis documented underreporting of race and ethnicity, which limits the ability to assess generalizability. The EQUATOR Network provides reporting guidelines that can help researchers meet reporting standards.

What are the consequences of underrepresentation in research?

Underrepresentation raises concerns about the generalizability of findings and limited benefits for underserved populations. The All of Us Research Program analysis raised concerns about the generalizability of findings in studies that use these data and limited benefits for the already underserved blind and deaf populations. The EClinicalMedicine article on ethnic minority and migrant underrepresentation in Covid-19 research noted that some migrant groups' concerns around the vaccine were due to their lack of inclusion in the clinical trials.

How can researchers set realistic inclusion targets?

Inclusion targets should be grounded in the epidemiology of the condition being studied and should be specific, measurable, and tied to the research question. Researchers should review the literature on disease prevalence, severity, and outcomes across demographic groups before finalizing eligibility criteria. The Glasgow hypertension survey focused on South Asian and African communities because of evidence for ethnic differences in treatment response and outcomes.

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References and Further Reading

• Research Data Framework. National Institute of Standards and Technology.
• EQUATOR Network. EQUATOR Network.
• Experimental Design Assistant. NC3Rs.
• NCBI Literature Resources. National Center for Biotechnology Information.
• PubMed. National Library of Medicine.
• The underrepresentation of racial/ethnic minorities in research on co-use of nicotine, alcohol, and/or cannabis via ecological momentary assessment methods: A narrative review.. Drug and alcohol dependence, 2024.
• Sex and gender in neurodevelopmental conditions.. Nature reviews. Neurology, 2023.
• Underrepresentation of ethnic minorities in hypertension research-a survey of enablers and barriers among South Asian and African communities in Glasgow.. Trials, 2022.
• Sex-Specific Neurocognitive Impairment.. Neurologic clinics, 2023.
• Underrepresentation of Minorities and Underreporting of Race and Ethnicity in Crohn's Disease Clinical Trials.. Gastroenterology, 2022.
• Underrepresentation of blind and deaf participants in the All of Us Research Program.. Nature medicine, 2023.
• Addressing Asian American Misrepresentation and Underrepresentation in Research.. Ethnicity & disease, 2020.
• Diversity in emergency management scholarship.. Journal of emergency management (Weston, Mass.), 2019.
• Structure Performance and Constraints of Spice Value Chains in Homegarden Agroforestry Systems Evidence from Basketo Zone Southern Ethiopia. 2026.
• Exploring the association between women's empowerment and household dietary diversity in rural Armenia: a cross-sectional analysis.. 2026.
• Healthcare professionals' perspectives on the barriers and enablers of cancer clinical trial participation among Arabic-speaking cancer patients in Australia: a qualitative study.. 2026.
• Factors associated with continuous social participation among Japanese older adults with mild cognitive impairment: A longitudinal observational study in Japan.. 2026.
• Confronting legacies of underrepresentation in clinical trials: The case for greater diversity in research.. Neuron, 2022.
• Ethnic minority and migrant underrepresentation in Covid-19 research: Causes and solutions. EClinicalMedicine, 2021.
• Underrepresentation of Hispanics and Other Minorities in Clinical Trials: Recruiters’ Perspectives. Journal of Racial and Ethnic Health Disparities, 2018.
• Gap and Underrepresentation of Gender and Minorities in Critical Care and Perioperative Medicine. Diversity Gender Equity and Inclusion in Critical Care and Perioperative Medicine A New Guidance for Team Excellence, 2025.
• Beyond underrepresentation: Constructing disability with Young Asian American children to preserve the "model minority" stereotype. Asia Pacific Journal of Research in Early Childhood Education, 2019.
• Intersectionality and underrepresentation among health care workforce: The case of Arab physicians in Israel. Israel Journal of Health Policy Research, 2015.

This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.