Trust, Familiar Places and Bilingual Staff Emerge as Keys to Diversifying Pediatric Research

Children and young people living with long-term conditions are among the most persistently underrepresented groups in medical research, and the treatments they receive are often built on evidence gathered from populations that do not look like them. A new systematic review published in Pediatric Research has, for the first time, brought together in a structured way what underserved children, young people and their caregivers actually want from research recruitment, and what strategies demonstrably work when researchers try to reach them. The findings offer a practical roadmap for a problem that has stubbornly resisted decades of good intentions.

The review, led by Ian J. Litchfield and Renuka P. Dias of the University of Birmingham together with colleagues, was conducted to rigorous systematic review standards and registered on PROSPERO. The team searched six major databases, including Embase, MEDLINE, CINAHL, PsycINFO, Scopus and the Cochrane Central Register of Controlled Trials, from their inception through to the end of September 2025. The scale of the sift was formidable: 18,669 records were retrieved, and after duplicates were removed the titles and abstracts of 16,727 articles were screened. Just 220 publications survived to full-text assessment, and only 21 studies, published between 1998 and 2024, ultimately met the inclusion criteria.

Those criteria were deliberately precise. Studies had to be conducted in high-income countries and to involve children and young people under the age of 19 with a long-term condition, along with their parents or caregivers, drawn from populations defined as underserved: those experiencing economic deprivation, geographic isolation, or belonging to racial and ethnic minorities. Every one of the 21 included studies came from the United States, and participants were predominantly drawn from African American and Latino communities. Seven studies focused primarily on the preferences of children, young people and caregivers, while fourteen reported the real-world effectiveness of recruitment and retention strategies embedded within larger clinical trials and observational studies of conditions including obesity, asthma, diabetes, sickle cell disease and cancer.

To make sense of this heterogeneous evidence, the researchers organised every strategy into four design components: access and environment, covering where research activities take place; communication and understanding, covering language, vocabulary and modes of outreach; the study facilitator, covering who delivers the research and how relationships are built; and targeted incentivisation, covering measures introduced specifically to support participation. This framework allowed the authors to compare approaches across studies that would otherwise resist comparison, and it revealed strikingly consistent patterns.

On access and environment, the message was unambiguous. Children and caregivers preferred study venues that felt safe, friendly and authentic, in sharp contrast to the sterile, adult-oriented atmosphere of many clinical facilities. Families described conflicts between study visits and school hours, the burden of transportation, and a clear preference for shorter appointments. In the effectiveness studies, recruitment rates were higher when families were approached at community events rather than in clinics, and particularly at culturally specific events. Schools and churches featured as promising recruitment sites, although the authors note that school-based research, despite being championed for nearly two decades, remains constrained by governance hurdles and the logistical strain on busy educational institutions.

Communication emerged as the second pillar. Families wanted study information in their own language, careful explanation of medical jargon, and active demonstrations of what participation would actually involve. Six studies reported benefits from linguistic adaptation, with five providing interpreters for Spanish-speaking families and three translating study materials into Spanish. Educational games and social media were valued, particularly by young people themselves, and one study described a research symposium where families living with the same condition learned about research together. Notably, families also wanted to hear about research from their own doctor, a finding that underscores the enduring authority of trusted clinicians even among populations otherwise wary of mainstream healthcare organisations.

The role of the study facilitator proved central to both recruitment and retention. Across multiple studies, participants emphasised the importance of trusting, mutually respectful relationships with the people delivering research, and several noted that facilitators sharing the same racial or cultural background engendered trust more readily. Continuity mattered too: two studies found that keeping contact with familiar members of the medical team throughout participation supported engagement, and one cancer study that used the same facilitator throughout reported positive retention outcomes. In the effectiveness data, culturally and linguistically congruent staff were associated with higher recruitment in a type 1 diabetes study, and good relationships with staff, including consistent contact with the same researcher, improved retention.

Targeted incentives and study design choices showed measurable effects as well. Recruitment following screening of eligible participants outperformed passive methods, and opt-out approaches yielded higher recruitment than traditional opt-in consent, although the review notes that opt-out recruitment may come at the cost of lower retention later. Financial incentives and small gifts improved retention, and one asthma study reported better retention where the intervention itself had been co-produced with participants and other stakeholders. Co-production of recruitment strategies and interventions, the authors suggest, may be among the most broadly influential approaches, giving underserved communities a genuine voice in shaping research, although they caution that co-design processes can themselves reproduce the same participation imbalances they aim to fix.

The review is candid about its limitations. There was a lack of comparative evidence across individual approaches, with most included studies descriptive in nature and few reliably isolating the effect of any single component. The rationale behind researchers’ choices of strategy was often poorly documented. The entire evidence base is American, focused predominantly on African American and Latino populations, which limits generalisability, although the authors observe that the findings mirror the broader literature on engaging underserved adults. Retention, in particular, remains under-evaluated relative to recruitment, a imbalance the authors say future large-scale studies must correct by giving equal attention to both.

Perhaps the review’s most consequential conclusion is economic. Successfully engaging underserved children and young people places additional demands on the time and resources of clinicians, care organisations and researchers, and those increased costs can make funding bids less competitive. The authors argue that funders and policymakers must explicitly acknowledge and resource this extra burden, warning that without adequate investment, the evidence base will continue to reflect only the populations that are easiest to reach. More representative research, they contend, will ultimately produce policies and treatments that serve the whole population, recouping the investment through more efficient use of healthcare services. For a field in which the treatments given to the sickest children rest on evidence from the fewest of them, that argument is difficult to ignore.

Subject of Research: Strategies to increase participant diversity in pediatric research among underserved children and young people with long-term conditions

Article Title: Strategies to increase participant diversity in pediatric research: a systematic review

Article References: Litchfield, I. J., Boiko, O., Sheldon, R., Sheth, V., Perera, T. W., Greenfield, S. M., & Dias, R. P. (2026). Strategies to increase participant diversity in pediatric research: a systematic review. Pediatric Research. https://doi.org/10.1038/s41390-026-05536-w

Image Credits: AI Generated

DOI: 10.1038/s41390-026-05536-w

Keywords: pediatric research, participant diversity, systematic review, recruitment strategies, retention, health equity, underserved populations, long-term conditions, community engagement, bilingual communication, co-production, clinical trials