Rare Diseases: How Language and Format Affect Inclusive Study Recruitment and Recommendations to Mitigate this


Clinical Research, especially for rare diseases, can have life-changing effects on those affected. With fewer eligible participants and difficulty gathering reliable and appropriate data for research, ensuring data is representative of the disease population is paramount to shaping the landscape for diagnosing and treating rare diseases. To do this, recruiting diverse populations from all backgrounds is key, whilst also appreciating the social, economic, and language barriers that could hinder progress. This essay will focus on language and format barriers in recruiting participants for rare disease research with various aspects of language and formatting being discussed.


When presenting research to potential participants, there is often a tendency to use jargon or technical language which usually reflects the nature of the proposed study. However, this can be exclusionary as it assumes all of those who are eligible to participate have an appropriate medical background, and can form an emotional connection to the study, irrespective of scientific background or knowledge of the field. Whether for personal reasons or altruistic purposes, patients may be more likely to participate in research if they can connect to the study (Sikweyiya & Jewkes, 2013). This concept has been studied by Hallowell et al., 2010 who found that the motives for research participation in genetics research are often a delicate interplay between various social factors, including personal, familial and societal. This study examined the reasons for study participation and found that a common theme was an emotional connection to the study/potential impact of the study to some degree. As such, appealing to this side of potential participants is key to improving recruitment for rare diseases, especially as the stakes are often higher due to the lack of research for a lot of rare diseases. The use of technical language can hinder the formation of this emotional connection. By using niche terminology and jargon, a perception of ‘research not being intended for me’ can be created, forming a barrier for potential participants. This applies to other forms of exclusionary language such as “experts in the field” etc. By implying that certain demographics are ‘ineligible’ to participate in studies, it can discourage potential participants.

Another way language can be exclusionary is if study materials and promotional/educational information are delivered in just one language. In a diversifying population, offering information in multiple languages is an important way to appeal to a larger group of people. For example, if all materials and study information are provided in English, those who do not speak English fluently or do not have English as their first language may not form the emotional compulsion to participate, as there is a disconnect caused by the language barrier. A systematic analysis by Muthukumar, Morrell & Bierer, 2021 explored this further, where it was found that those who have limited English proficiency are routinely excluded from participating in clinical trials in the USA. This reduces the generalisability of the results of studies as recruitment efforts are not totally inclusive, marginalising certain groups and reducing how accurately the cohort represents the broader population. As such, it can be more difficult to draw accurate conclusions from the results or make recommendations that can apply to a range of communities. This can ultimately lead to research waste and an underrepresentation of marginalised groups. In turn, this can inadvertently perpetuate healthcare inequalities and systemic biases, leading to inequitable access to the potential benefits of the research.


However, this narrative of the effects of language on recruiting individuals from marginalised groups can be applied to the format for study recruitment. Accessibility for those with disabilities can be limited in research, such as recruitment materials relying heavily on printed materials or inaccessible websites, which can exclude those with visual impairments. Crook et al., 2016 described the effect of accessibility on recruitment further, specifically for those with learning disabilities. By asking individuals with learning difficulties about their opinions on participating in research, they found that if research is difficult to understand, it can be a barrier for those with learning disabilities to take part. This isn’t limited to those with disabilities, however. Relying on virtual means to recruit participants too heavily can exclude those of reduced digital literacy (which often includes elderly patients) and those of lower socioeconomic status who may not have access to the internet. As such, it is imperative to diversify the method and means through which recruitment for rare disease studies is conducted. A mixed-medium approach could be useful for this purpose – virtual, in-person, audio, tactile and visual methods for recruitment can help ensure no groups are being inadvertently excluded from participating in research.

Perpetuating Health Inequality:

A lack of accessibility to clinical research can perpetuate barriers to healthcare that marginalised groups may experience, especially in rare disease research. As is usually the case, such little information surrounding the management of these diseases means it is more imperative than ever to recruit participants that represent the entire population of those who have the disease. This is irrespective of language, culture, race, socio-economic status, age or geographical location. By not doing so, health inequalities can be perpetuated. One example of this is delayed or misdiagnosis. Rare diseases are often difficult to diagnose due to a low prevalence, and a lack of knowledge of them among healthcare professionals. If certain patient groups are underrepresented in clinical trials, the potentially diverse manifestations of the disease can be missed, delaying the diagnosis or even preventing the diagnosis of the disease, thus prolonging the period of suffering and limiting care options. This can lead to limited options for treatment too, as in most cases there is not a ‘one-size-fits-all’ approach to treatment, and the management of the disease often needs to be tailored to the needs of the patient group, thus limiting access to cutting-edge treatments.

This issue extends further than the microcosm of immediate diagnosis and treatment for patient groups. The lack of a representative study cohort can have social effects, which may in turn affect the landscape for rare diseases. When individuals from underrepresented groups are excluded from rare disease research, their stories and experiences are not always heard, thus hindering awareness campaigns and advocacy efforts. As a result, this can make it difficult to mobilise resources, support and funding for further research and the development of treatments, including orphan drugs which are developed to treat rare diseases. A lack of inclusivity in research can result in some communities experiencing higher barriers to obtaining these drugs, resulting in unequal health outcomes.

There are, however, many ways to diversify clinical trial recruitment. To uncover the most effective ways to recruit participants, it could be helpful to conduct pilot studies to test recruitment strategies. Some studies have focussed on the effects of different strategies on recruitment. Iflaifel et al., 2023 explored this by conducting interviews and focus groups to explore different methods for study recruitment. Whilst online methods were, overall, more favourable and accessible to most, this method was deemed less trustworthy and secure, with in-person methods permitting participants to build a rapport with healthcare providers. They noted that all participants agreed that using a hybrid approach to recruiting participants integrating online and offline methods would help widen participation in mental health research.

Taking into consideration what the public believes to be appropriate is the best way to ascertain how best to recruit participants. By gathering a consensus on how people prefer to be approached/offered opportunities to be part of research, it is possible to implement tailored strategies to maximise diversity and inclusivity for the population of individuals with a specific rare disease. This was confirmed by Bendixen, Morgenroth & Clinard, 2016 when they qualitatively investigated attitudes and perceptions of engagement in rare disease research, specifically focusing on Duchenne Muscular Dystrophy. They conducted focus group sessions at geographically and demographically variable locations in the USA and found that it was paramount to engage families in recruitment strategies for rare disease research recruitment. Open and in-depth conversations about research with families were found to be invaluable in building trust towards research and preventing fragmented information from deterring patients from participating in research. As such, having a family-centred approach can help reduce the stigma surrounding clinical research, helping build an emotional connection to research and prompting involvement.


To conclude, rare disease research is vital to finding out more about pathologies that we may not know much about. However, for the benefits of research to be truly applicable to everyone, it is important to diversify recruitment strategies to ensure the research is inclusive. This is difficult to do in rare disease research as the pool of eligible participants is already low, so strong efforts should be made to recruit as diverse a cohort as possible, taking a patient-oriented approach to developing effective frameworks and plans for recruitment.


Bendixen, R.M., Morgenroth, L.P. and Clinard, K.L. (2016) ‘Engaging Participants in Rare Disease Research: A Qualitative Study of Duchenne Muscular Dystrophy’, Clinical Therapeutics, 38(6), pp. 1474-1484.e2. Available at: https://doi.org/10.1016/j.clinthera.2016.04.001.

Crook, B. et al. (2016) ‘“So often they do not get recruited”: exploring service user and staff perspectives on participation in learning disability research and the barriers that inhibit it’, British Journal of Learning Disabilities, 44(2), pp. 130–137. Available at: https://doi.org/10.1111/bld.12120.

Hallowell, N. et al. (2010) ‘An investigation of patients’ motivations for their participation in genetics-related research’, Journal of Medical Ethics, 36(1), pp. 37–45. Available at: https://doi.org/10.1136/jme.2009.029264.

Iflaifel, M. et al. (2023) ‘Widening participation – recruitment methods in mental health randomised controlled trials: a qualitative study’, BMC Medical Research Methodology, 23(1), pp. 1–12. Available at: https://doi.org/10.1186/s12874-023-02032-1.

Muthukumar, A.V., Morrell, W. and Bierer, B.E. (2021) ‘Evaluating the frequency of English language requirements in clinical trial eligibility criteria: A systematic analysis using ClinicalTrials.gov’, PLOS Medicine, 18(9), p. e1003758. Available at: https://doi.org/10.1371/journal.pmed.1003758.

Sikweyiya, Y. and Jewkes, R. (2013) ‘Potential Motivations For and Perceived Risks In Research Participation: Ethics in Health Research’, Qualitative Health Research, 23(7), pp. 999–1009. Available at: https://doi.org/10.1177/1049732313490076.

Please sign in or register for FREE

If you are a registered user on Research Communities by Springer Nature, please sign in

Subscribe to the Topic

Clinical Medicine
Life Sciences > Health Sciences > Clinical Medicine
Clinical Research
Life Sciences > Health Sciences > Biomedical Research > Clinical Research
Clinical Trials
Life Sciences > Health Sciences > Biomedical Research > Clinical Research > Clinical Trials
Clinical Trial Design
Life Sciences > Health Sciences > Biomedical Research > Clinical Research > Clinical Trials > Clinical Trial Design