Abstract
In Parkinson's disease (PD), inclusive research recruitment practices are essential to ensure that study findings are generalizable to diverse populations. The definition and implementation of inclusive recruitment practices are guided by the principles of equity, justice, engagement, and sustainability. However, practical implementation guidance is lacking. This paper shares insights from the Black and African American Connections to Parkinson's Disease (BLAAC PD) study, a PD genetics research study being conducted in the United States that enrolls individuals with and without PD. The inclusive recruitment strategy in BLAAC PD centers around four areas: training and working with study personnel toward equitable research practices, partnering with community members, creating culturally resonant study materials, and customizing practices at the local level. We provide practical examples implemented by BLAAC PD to address each of these areas. We share the materials and tools that the study utilizes for site training, recruitment, and community outreach and engagement. These approaches have potential for application in other PD research studies, to achieve greater diversity in PD research.
Background
The underrepresentation of ancestral, racial, and ethnic groups in Parkinson's disease (PD) research creates an obstacle to a comprehensive genetic, biological, and clinical understanding of the disease1,2 and limits the generalizability of results. 3 Inclusive approaches to engaging and recruiting people who are underrepresented in PD research can address gaps in clinical research and ultimately improve health outcomes for all.4,5
Increased awareness of health disparities and the need to advance health equity have prompted the call for inclusive, equitable, and culturally responsive approaches to research. 6 For example, in 2024 the U.S. Food and Drug Administration published draft guidance encouraging study sponsors to develop Diversity Action Plans for enrolling underrepresented populations in clinical studies. 7
Inclusive approaches are defined as those that promote the presence of differences such as race, gender, religion, sexual orientation, ethnicity, nationality, socioeconomic status, language, (dis)ability, age, religious commitment, or political perspective. 6 Inclusive approaches to engaging and enrolling participants in research studies are clearly needed to advance medical science, foster health equity, and rebuild trust with historically marginalized communities. Several groups have put forth data, guidelines, recommendations, and strategies to increase diversity and equity in clinical research.8–13 Emerging data from research in PD and other neurodegenerative diseases may represent preliminary signs of success.9,14,15 However, a lack of diversity in PD research studies remains a major problem. 16 Practical guidance on how to accomplish inclusive recruitment practices that lead to increased diversity in PD clinical research studies could thus be of value.
Parkinson's genetics research represents an important example of the critical need for inclusive recruitment practices.17,18 Since the initial discovery of genes that contribute to PD in 1997, 15 much progress has been made in our understanding of the genetic contributions to PD. However, until recently, the majority of PD genetics studies lacked racial and ethnic diversity, and much of what was known about PD genetics came from study samples of predominantly European ancestry.19,20 To address critical knowledge gaps around the genetic architecture of PD, the Aligning Science Across Parkinson's (ASAP) initiative 21 launched the Global Parkinson's Genetics Program (GP2). 22 GP2 and its contributors aim to collect data and genetic information from over 250,000 individuals worldwide.22,23
To increase enrollment of people who identify as Black or African American in GP2 in the United States, GP2 initiated the Black and African American Connections to Parkinson's disease (BLAAC PD) 24 study in 2021.25,26 Participants with and without PD are enrolled in BLAAC PD at twelve sites in the United States for a one-time visit that includes clinical assessments and blood or saliva collection for genotyping. De-identified data are shared with GP2 for integration into the program's open-access dataset. 27 The BLAAC PD study is ongoing and, as of August 2025, has enrolled over 350 individuals with PD and over 500 individuals without PD who identify as Black or African American.
The strategy for inclusive recruitment practices and community engagement for BLAAC PD centers around four areas: training and working with study personnel toward equitable research practices, partnering with community members, creating culturally resonant study materials, and customizing practices at the local level. Herein, we describe the experience of the BLAAC PD study, sharing practical examples of actions taken to institute inclusive recruitment practices in engaging with individuals and communities for PD research.
Methods
Since 2022, ASAP's implementation partner, The Michael J. Fox Foundation for Parkinson's Research (MJFF), has collaborated with NORC at the University of Chicago to provide sites with training and technical assistance to promote the engagement and recruitment of people who identify as Black or African American.
The strategy for inclusive recruitment practices and recommendations detailed here stems from a variety of sources including: (1) expertise and experience of MJFF in engaging with the PD community, (2) NORC staff expertise in community-engaged, inclusive, equitable and culturally responsive research, (3) a literature review of the most fundamental aspects of engaging and successfully recruiting people from underrepresented populations for medical/clinical studies, (4) continuing inputs from study teams and subject matter experts, and (5) recommendations from a six-member BLAAC PD Advisory Board convened in 2022 by MJFF to provide strategic guidance and generate recommendations for expansion of the BLAAC PD program. Three of the six Advisory Board members are part of the Black and African American community and the Advisory Board's collective expertise included lived experience as family members of people with PD and as study participants. Other members of the advisory board had experience and/or expertise in clinical care of individuals with PD, scientific expertise in health equity, community-based research, health communication, and translational epidemiology.
Inclusive recruitment practices: Principles and practical examples
The definition and implementation of inclusive recruitment practices in BLAAC PD were guided by four principles: equity, justice, engagement, and sustainability. Practical approaches and recommendations to realize each principle informed the strategy utilized in BLAAC PD. The four principles are described below, along with recommendations for: (1) training and working with study personnel toward equitable research practices, (2) partnering with community members to strengthen study design and outreach, (3) creating clear, compelling, culturally resonant study materials, and (4) exploring and customizing local recruitment methods. Examples from the BLAAC PD experience are provided, where applicable.
Inclusive recruitment practices have been a top priority for GP2 and BLAAC PD. Site selection, study teams, and the study protocol were all evaluated or created with these principles in mind. The study protocol was designed to prioritize answering key scientific questions while minimizing participant burden. As described elsewhere, 25 the BLAAC PD study protocol includes collection of a DNA sample and basic information on demographics, PD duration and characteristics, family history, the Clinical Impressions Severity Index for Parkinson's Disease (CISI-PD), olfactory testing, and levodopa intake. Subsequent protocol amendments have added cognitive testing, other non-motor assessments, and environmental/lifestyle measures.
BLAAC PD ensures engagement with and input from community members in an ongoing and iterative process. Feedback from and communication with the BLAAC PD Advisory Board and other community members were obtained during the initial study setup and over time when study amendments were instituted. Anecdotal feedback from potential and existing BLAAC PD participants also informs study modifications.
The approach to inclusive recruitment practices in BLAAC PD has been dynamic and is evolving as the study continues. MJFF, NORC, and site teams meet quarterly. Guest speakers such as genetic counselors and recruitment specialists are invited to these meetings. In a semi-structured format, sites and experts share experiences. Established best practices toward the study's enrollment goals are integrated when applicable and implemented study-wide. Practical examples of how these principles were applied in BLAAC PD are provided below and/or in Tables 1–4 and Supplementary Materials.
How to train and work with study personnel to institute inclusive recruitment practices: approaches, recommendations, and examples.
How to partner with community members to strengthen study design and outreach: approaches, recommendations, and examples.
Creating clear, compelling, and culturally resonant study materials: approaches, recommendations, and examples.
Approaches, recommendations, and examples for exploring local recruitment methods.
Equity: Eliminating inequities in knowledge & treatment
Equity in access to and delivery of high-quality healthcare is a critical prerequisite for equity in clinical research. Health inequities in PD are well documented, especially racial, ethnic, and geographic (rural vs. urban) disparities in PD diagnosis and treatment. 28 While addressing these inequities requires systemic changes across multiple areas beyond the scope of BLAAC PD as a study, they are a key priority within the clinical care delivery systems at study sites.
As with any research study, ensuring that participants are aware of and maintain their agency while participating is essential. 29 One way to encourage and maintain participant empowerment is to be open and transparent about the nature of research being conducted. This includes proactively sharing information such as why the study is being conducted, what participants will be asked to do in the study, and how their samples will be secured and used.30,31 Awareness of health literacy challenges is important. 32 It is recommended that patient-facing health information not exceed an eight-grade reading level in the United States, 33 though in some settings, lower reading levels may be more appropriate. This is particularly relevant when study-related goals or assessments that are going to be discussed with potential participants relate to complex concepts such as genetics. Active feedback from community partners is invaluable as messaging around the study and its value proposition are conceptualized and developed. Recognizing the diversity of communities (across and among demographic groups) requires tailoring materials and approaches to reflect that diversity, which will increase trust and willingness to participate. 34 In turn, this will improve the breadth of scientific knowledge on PD across racial, ethnic, and ancestral groups.
In BLAAC PD, ensuring that participants were aware of and understood various aspects of the study and the meaning and implications of their participation was achieved in several ways. As in most studies, the informed consent form (ICF) content was of particular priority. Site team members were trained on the informed consent process (Table 1).35,36 In addition, the study partnered with community members to ensure the ICF and other study materials were informative and understandable (Table 2). Specifically, Black or African American individuals with PD and/or their family members provided feedback on the ICF, protocol revisions, and recruitment materials, and their feedback was incorporated. For example, when the study modified one of its case report forms to collect more detailed information on family history, community members reviewed a draft of the form. Their feedback highlighted the need to more clearly explain the difference between a full sibling and a half sibling, and the family history case report form was revised to incorporate this information.
Furthermore, several participant-facing materials in different formats were created and distributed to sites to help inform and educate potential participants (Table 3 and Supplementary Material). Community feedback was solicited in the development of such materials, and materials were revised accordingly. Images were intentionally inclusive and representative. Wording on study materials was simple, with a clear message, while also being informative. An annotated example of a study flyer is shown in Figure 1, and other examples of materials developed for BLAAC PD are provided in the supplement including flyers and brochures (supplement pages 10–19), frequently asked questions (FAQs) (supplement pages 20–26), participant newsletter (supplement pages 27–31), and partner toolkit (supplement pages 32–37), including social media outreach examples (supplement page 37). Study teams, and especially study coordinators, received talking points and ongoing training and support to provide them with the knowledge, communication skills, and confidence to speak about complex topics such as PD genetics and data privacy. At regularly scheduled meetings that brought teams together within and across sites, site teams shared their experiences, including which approaches seemed more successful than others, and where additional training or support was needed.

Annotated example of BLAAC PD flyer explaining inclusive design considerations.
Finally, it is crucial to acknowledge that we all carry preconceived and often subconscious biases and stereotypes. Maintaining a self-reflective approach and checking one's biases throughout the recruitment and engagement process can help to build mutual trust with individuals eligible for the study. 34 In BLAAC PD, unconscious bias and other related topics were addressed in a webinar presented to site teams (see below).
Justice: Address past and present injustices
Cases of historical medical exploitation are well-documented (e.g., the Tuskegee study, Henrietta Lacks, and the Havasupai tribe).37,38 As such, it is important to be mindful of attitudes that minoritized communities may hold toward medical research. It is crucial to recognize that these attitudes are based on both historical and contemporary experiences. Even if current community members were not alive during the era of segregated care delivery and abuses of people of color in the context of science, communities recall medical and institutional racism. Moreover, this legacy is augmented by ongoing experiences of discriminatory practices that contemporary individuals face when interacting with the medical community.39,40
One reported best practice for addressing mistrust toward the medical profession is for health care providers and study teams to acknowledge and denounce well-known cases of historical medical exploitation.29,41 This recommendation was echoed by BLAAC PD Advisory Board members, who stressed the importance of acknowledging historical racism in communication with participants. Additionally, the study FAQ pointedly discusses the allowed uses for all contributed study data and samples (Supplementary Material).
Engagement & sustainability: Engage local communities in reciprocal relationships and sustain relationships beyond the scope of the study
Engagement with Community Members
For successful engagement of local communities—the communities from which the study is recruiting participants—resources and training for skills development or capacity building for the study teams are a core component of improving diversity in research cohorts (Table 4).42,43 Co-learning forums where sites share their own wins and challenges are helpful engagement and learning tools. Training sites in best practices for communication is a critical component. 44 The training session may benefit from discussing and modeling communication skills to engage potential study participants in clinic and community settings. A brief didactic presentation on communication skills and decision-making processes in recruitment, followed by group role-play exercises practicing common recruitment scenarios, is one possible format. Topics may include verbal and non-verbal communication approaches to build rapport and trust, potential study participants’ decision-making processes and questions, and communication strategies to support decisions to participate or not in the study. Webinars with ample opportunity for questions and discussion may be a useful format to deliver key information to study sites.
In BLAAC PD, a range of topics were covered in BLAAC PD forums and training, including basics of PD genetics, forms of media, how to best utilize health fairs for recruitment, development of various communication skills, and communication around complex topics. To improve communication about genetics with participants, webinars covered basics of how to explain genetics and genetics research, basics of genetic counseling, and importance of genetics research to understanding of PD. Another session covered specific and intentional strategies to engage the Black and African American community in research, featuring a PD researcher working externally to BLAAC PD. Opportunities for coordinators to share their lived experiences and practical strategies and/or workflow changes to support BLAAC PD recruitment also fostered co-learning and collaboration.
Engagement with Community-Based Organizations
Literature underscores the need to engage and develop local reciprocal relationships with community-based organizations in which a mutual exchange of support occurs between both partners.40,41 Study sites could seek to establish connections with local community-based organizations (CBOs), whether organizations focused on PD or not, emphasizing how study involvement could help CBOs further their goals of community support. It is important that sites consider what other value they could offer, such as disease education and facilitation of clinical care.
When forming relationships with CBOs, collaborative decision-making can build trusting relationships, engendering knowledge co-production and exchange for relevant, actionable evidence that best serves communities.45,46 Understanding the value proposition of the study from the perspective of the CBOs/communities requires sites to learn from the CBOs about their perspectives and needs, as well as concerns of community leaders/members.8,34 One recommended approach toward establishing collaborative engagement between a site and CBO/community is to form dyads or breakout groups for open, reciprocal discussions that pair CBO leaders/community members and site staff members, and have the pairs report on a particular decision to the larger group.47,48
There are several barriers that may impede CBO engagement with research studies. Barriers include poor study infrastructure, lack of staff continuity, and/or no sustainability plan. 42 CBOs may be hesitant to engage if they expect a partnership to be temporary and predicated on their involvement with a particular project (i.e., the study). Acknowledging barriers and setting expectations at the outset that collaboration, consistent communication, and joint work with the CBO is intended to be a long-term commitment — and then acting on that commitment — can facilitate successful engagement with local organizations. 49 Additionally, reporting back on how suggestions were integrated or considered can build trust and support sustainability.
At the local level, BLAAC PD study sites engaged with the community and CBOs in various settings, including health fairs, educational institutions, and community health centers. Health fairs are viable engagement and recruitment methods; however, in the context of PD research, are more likely to result in recruitment of controls rather than PD cases. Table 5 provides tips for planning, attending and following up at health fairs and other community-driven health initiatives as part of engagement and recruitment efforts. Events are best attended by staff with local familiarity and connection to facilitate communication and trust building. 50 For example, many BLAAC PD study teams are engaged with entities that either organize or attend health fairs. The health fairs may be general community health fairs or those specific to older adults or certain communities, such as the Black or African American community. Study teams attended these health fairs, setting up booths to provide attendees with information about PD, PD research, and BLAAC PD. In addition to educational materials around PD and brain health, study teams provided attendees with some “stuff we all get” (SWAG), such as T-shirts and hats with the study logo.
Strategies and tips for attending community health fairs or other off-site events.
It is important that the study teams engage with the community and specific CBOs beyond a single health fair. Consistent presence and engagement at health fairs can be meaningful, not only to community members in attendance, but also to community leaders and CBOs who may have booths at these fairs. Thus, the goal for the research team is to develop a bidirectional and mutually beneficial relationship with CBOs. BLAAC PD site teams provide seminars and materials to educate CBO staff or community members about PD 36 and research in general. Beyond health education and research, some study sites used creative engagement approaches such as holding Bingo events at senior citizen centers.
Media campaigns
Common recruitment efforts may also include owned, earned, or paid media campaigns. A sample presentation on this topic, used for the BLAAC PD study, is included in the Supplementary Material. Another common recruitment effort is to use direct mail, shown to be more effective at recruiting historically marginalized populations than mass media. 51 In the Supplementary Material (pages 10–26), we provide recruitment materials from the BLAAC PD and GP2 program for reference and adaptation.
Discussion
Drawing upon prior experience, contributions from study sites, and real-time study activities, we have presented a strategy for inclusive research recruitment and community engagement, providing practical examples of implementation and resources utilized in the BLAAC PD study to recruit individuals in the United States with and without PD who identify as Black or African American. The strategy and tools used to implement it may be applied globally to a broad array of PD clinical research studies that seek to engage and recruit ethnically/racially diverse groups for more inclusive disease understanding and treatment development. That said, a key observation is that approaches to recruiting groups underrepresented in research must be adapted 52 ; transferability of the specific approaches for inclusive practices we describe will likely require modification depending on the context of use. One ‘size’ or set of offerings does not fit all, and racial/ethnic communities cannot be viewed as a monolith. Within the context of a multi-site study, approaches to culturally responsive engagement and recruitment must be tailored to the local community's unique needs and preferences. Partnering with members from the community, and obtaining input from them and study participants over time, is critical toward understanding the latter. For example, in BLAAC PD, regional differences in preferred terminology were noted, and study materials and messaging were modified accordingly. In addition, adaptation of site team building, training, and, more broadly, design and implementation of study operations requires consideration of the sites’ unique resources, capacities, and challenges. In areas with limited local resources for PD research, partnering with national and international PD organizations and foundations could be useful.
In the context of PD research, a main goal of inclusive recruitment practices is to increase diversity in PD research cohorts. This allows for improved generalizability of research results to the PD population. On the other hand, in PD genetics research in particular, cohort diversity is critical towards informing development and delivery of personalized care. Thus, whether improving our understanding of PD at the population level or informing knowledge of PD at the individual level, the ultimate measure of success of inclusive recruitment practices over the long-term is reduced disparities and, ultimately, equity in delivery of care to all people with PD. However, in the shorter-term, some measures of success may be considered.
Keeping in mind that inclusive recruitment practices, such as team building and community engagement programs, are an ongoing process to establish enduring partnerships rather than short-term transactional relationships, one broad measure of the impact of inclusive recruitment practices is the success of a given study in its recruitment goals. This is exemplified, for example, in BLAAC PD's success to date in recruiting a sample traditionally under-represented in PD research, including recruitment of the majority of controls through efforts related to community engagement. 53 Further research is needed to understand how to tailor these and other strategies for inclusive recruitment practices for other clinical research settings and goals (e.g., institutions of different sizes, geographic regions, populations of focus). This work could shed light on appropriateness of content within a given context, project roles, necessary adaptations, feasibility, and potential for sustainability. An outcomes-focused evaluation could also determine whether the strategy is practical and actionable (i.e., suitable for everyday use), responsive to the needs of the field, and contributes to inclusive recruitment practices for clinical research. Such an outcomes evaluation could include metrics on uptake (e.g., number of downloads, page views of online study-related information), cost-benefit analyses, and qualitative measures (e.g., focus groups and key informant interviews conducted with different types of clinicians and administrators) to test user experience and identify potential areas for improvement.
The need to improve diversity in PD research cohorts is widely recognized. Here, we present the strategy being implemented in BLAAC PD to support inclusive recruitment, including a compendium of actionable tips and approaches for PD researchers and study teams. We recognize that this and similar strategies will require systematic evaluation to better understand their effectiveness, potential applications, and how key elements may need to be adapted across settings. We encourage PD researchers to explore, apply, and adapt these and other inclusive recruitment practices to advance diversity in Parkinson's disease research.
Supplemental Material
sj-pptx-1-pkn-10.1177_1877718X261440708 - Supplemental material for Practical approaches to inclusive recruitment practices in Parkinson's disease research
Supplemental material, sj-pptx-1-pkn-10.1177_1877718X261440708 for Practical approaches to inclusive recruitment practices in Parkinson's disease research by Lana M Chahine, Naomi Louie, Elizabeth Disbrow, Alexis Marbach, Samantha Augenbraun, Bao-Tran Nguyen, Ashani Johnson-Turbes, Carly Parry, Sabrina Avripas, Shivika Chandra, Marissa Dean, Erin R Foster, Deborah Hall, Vanessa Hinson, Camilla Kilbane, Scott A Norris, Ashley Rawls, Cabell Jonas, Ejaz A Shamim, Lisa Shulman, Julia Staisch, Erin Furr Stimming, Tao Xie, Mackenzie Wilcox, Andrew Ameri, Sarah Breaux, Mahesh Padmanaban, Rainer von Coelln, Andrew Singleton, Cornelis Blauwendraat, Sara Bandres-Ciga, Eda Baykal-Caglar, Caitlin Kelliher, Kayleigh Greenwood, Alyssa O'Grady, J Solle, Catherine M Kopil, Maggie McGuire Kuhl and On Behalf of the Black and African American Connections to Parkinson's Disease (BLAAC PD) and the Global Parkinson's Genetics Program (GP) in Journal of Parkinson's Disease
Footnotes
Author contributions
Writing of manuscript: Lana M. Chahine, Naomi Louie, Elizabeth Disbrow, Maggie McGuire Kuhl, Alexis Marbach, Samantha Augenbraun, Bao-Tran Nguyen, Ashani Johnson-Turbes, Carly Parry, Sabrina Avripas
Review and revision: Shivika Chandra, Marissa Dean, Erin R. Foster, Deborah Hall, Vanessa Hinson, Camilla Kilbane, Scott Norris, Ashley Rawls, Ejaz A. Shamim, Lisa Shulman, Julia Staisch, Erin Furr Stimming, Tao Xie, Mackenzie Wilcox, Andrew Ameri, Sarah Breaux, Mahesh Padmanaban, Rainer von Coelln, Andrew Singleton, Cornelis Blauwendraat, Sara Bandres-Ciga, Eda Baykal-Caglar, Caitlin Kelliher, Kayleigh Greenwood, Alyssa O’Grady, J Solle, Catherine M. Kopil
Funding
This project was supported by the Global Parkinson's Genetics Program (GP2). GP2 is funded by the Aligning Science Across Parkinson's (ASAP) initiative and implemented by The Michael J. Fox Foundation for Parkinson's Research (https://gp2.org). For a complete list of GP2 members, see
. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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References
Supplementary Material
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