Clinical trials are essential for advancing healthcare, yet they often fail to adequately represent the diverse populations most affected by the conditions being studied. This article delves into the critical issue of under-served groups in clinical research, drawing upon stakeholder insights and expert analysis to propose a strategic roadmap for greater inclusivity. The journey began with an initial stakeholder meeting in March 2018, where a significant majority (74%) of participants expressed the lack of a consistent definition for ‘under-represented groups’ within clinical trials. This foundational concern highlighted the urgent need for clarity and action to ensure that clinical research truly benefits all segments of society.
Defining “Under-Served”: A Scoping Review of Key Definitions
To understand the scope of the challenge, a targeted scoping review was conducted to examine existing definitions of under-served groups. Analyzing 58 full-text papers, predominantly from the USA but also including global and other national data, revealed a consistent pattern across cancer and non-cancer research. Groups frequently identified as under-served included children, older adults, individuals with multiple health conditions, pregnant women, ethnic minorities, socioeconomically disadvantaged populations, those outside mainstream healthcare settings, and people with cognitive impairments. While much of the literature focused on specific subgroups, common barriers contributing to under-representation emerged. These included comorbidities, logistical obstacles such as transportation and remote study locations, inaccessible information due to language or format, mistrust or disengagement with healthcare systems, and a general lack of awareness about clinical trial opportunities. Crucially, the review reinforced the persistent under-representation of women and ethnic minorities in pivotal areas like cancer and cardiovascular disease trials. Furthermore, it exposed a significant gap in data collection and reporting, making it difficult to even assess the representation levels within many studies.
Stakeholder and Professional Perspectives on Under-Representation
To gather diverse perspectives, online surveys were distributed to both patient stakeholders and healthcare professionals. Among the 70 patient stakeholder respondents, a substantial 59% agreed on the ambiguity surrounding the meaning of “under-representation.” Similarly, among 101 professionals—including research nurses, academic researchers, clinical trial unit staff, and representatives from industry, NHS, PPI engagement, and charities—a majority of 56 respondents concurred that a universal definition of under-representation was unattainable.
Table 1, derived from stakeholder groups and surveys, outlines the diverse groups identified as under-served. Interestingly, a small number of respondents also suggested groups they did not consider under-served, including children, older people, frail individuals, those with multiple conditions, women, and socioeconomically disadvantaged groups. This overlap, yet absence of direct contradiction (no group was simultaneously labeled as both under-served and not under-served by the same respondent), underscores the nuanced and context-dependent nature of “under-served.”
Table 1 Under-served groups identified from stakeholder groups and surveys
Further qualitative data from twenty respondents who provided their own definitions of under-representation clustered around three themes: (1) inclusion, emphasizing poor access to trials for certain populations; (2) epidemiology, focusing on participant demographics not mirroring the real-world demographics of the target population; and (3) miscellaneous, capturing varied comments and observations. While some attempted direct definitions, others offered commentary, such as noting gender imbalances in recruitment despite non-gender-specific study designs. Table 2 summarizes the barriers to trial inclusion identified by both participant and professional surveys, highlighting the multifaceted challenges to overcome.
Table 2 Barriers to inclusion
Towards Consensus: Shifting the Focus to “Under-Served”
The insights from the literature review and surveys culminated in consensus meetings aimed at forging a path forward. A key outcome was the agreement to adopt “under-served groups” as the preferred terminology. This shift was deliberate, designed to move away from potentially blaming language and instead emphasize the responsibility of the research infrastructure to proactively provide suitable solutions and services to potential participants. The consensus also acknowledged the impracticality of a single, universal definition of “under-served.” Instead, the definition was deemed context-specific, characterized by a combination of factors: a disparity between the population affected by a condition and trial participants; limited opportunities to participate due to study design, logistical, or cultural barriers; and the unsuitability of interventions for specific groups due to physiological, logistical, or cultural considerations. Stakeholders then prioritized key actions for the coming year, all aimed at realizing the vision of “better healthcare through more inclusive research.” The top priorities included embedding research within healthcare systems to improve accessibility, developing resources and training for research teams and community stakeholders, encouraging funders to prioritize under-served groups, fostering patient-centeredness throughout the research process, launching a public awareness campaign about clinical trials, and establishing baseline measurements to track progress. This collaborative effort was branded as ‘Innovations in Clinical Trial Design and Delivery for the under-served’ (INCLUDE), marking a strategic commitment to this vital area.
Strategic Objectives and a Roadmap for Action
The project culminated in a final meeting where strategic goals were presented and refined. This led to the identification of four equally important objectives to guide future efforts: (A) fostering Community Partnered Participatory Research (CPPR) to build lasting relationships with under-served groups, (B) creating training resources for all stakeholders involved in designing and delivering trials for under-served populations, (C) developing infrastructure and systems to effectively reach, engage, recruit, and retain under-served groups, and (D) collaborating with funders, regulators, and other key stakeholders to dismantle funding, regulatory, and policy barriers hindering the inclusion of under-served groups.
Workstreams to take forward in the programme
To operationalize these objectives, four overlapping workstreams were established, as depicted in Figure 2. These workstreams provide a structured approach to tackling the multifaceted challenges of inclusivity in clinical research.
Roadmap to guide initiatives to improve inclusion of underserved groups into clinical research. Processes are embedded in the context of ethics and regulatory requirements and evolving digital technology developments. Boxes represent key points for considering inclusion of underserved groups over the lifecourse of the study
Finally, the culmination of surveys, literature reviews, and stakeholder meetings resulted in a strategic roadmap (Figure 3). This roadmap serves as a guide for groups aiming to address the specific needs of under-served populations and for researchers seeking to effectively collaborate with these communities. It is not intended as a prescriptive solution, as solutions must be tailored to each specific under-served group. Instead, it offers a framework for future research and targeted initiatives to overcome the identified barriers to participation. By embracing this roadmap and prioritizing the needs of under-served groups, the clinical research community can move closer to achieving truly inclusive research that benefits all members of society.
