Randomised controlled trials (RCTs), where study participants are randomly allocated to an experimental group or a control group, became the 'gold standard' of clinical research in the mid-20th century. [1] RCTs have historically enrolled proportionally more white men than people from other groups, with the thinking, at least in part, being that the results could be extrapolated to all populations. Subsequent research, however, has shown that this is not the case, as underrepresented groups may have different responses to the disease or drug, based on social, cultural and other contexts. [2] Diversity in clinical trials, which is about so much more than differences in biology, is therefore an essential part of ensuring that everyone has equitable access to the most effective and safest approaches to treatment.
The impact of a lack of diversity
Using drugs that haven't been tested in certain groups is a gamble. By excluding some people from clinical studies, companies are reducing the possibility of generalising their results to a broader population at launch, and potentially limiting the market (and therefore income) for their drug or device. The lack of diversity in clinical trials can also have a financial impact on healthcare provision, as drugs that are less effective in certain groups can affect quantity of life, quality of life and ability to work. [2] Looking at it from a purely economic perspective, while ensuring that clinical trials are fully diverse in the first place may appear more costly, it could save the cost of redoing studies to reach a wider market at a later date.
Recruitment and retention are a huge challenge for companies running clinical trials, and a lot of time and money is lost when clinical trials fail through lack of participants. Studies looking at clinical trials funded by two UK funding bodies between 1994 and 2002 showed that less than a third recruited the number of patients that they needed, and of those given an extension of time and money, only one in five hit their recruitment target. [3] In an international study, the termination, suspension or discontinuation of over half of Phase I to Phase IV clinical trials between 2011 and 2021 was as a result of low accrual. [4] Repeating trials that fail part way through because of attrition, or restarting trials that didn't hit their recruitment target, is costly, and result in companies losing income as the drugs will either reach the market at a later date, or not reach the market at all.
Recruitment and retention may not appear to have a clear link with diversity, but making changes to clinical trials to improve diversity could have an impact on both initial recruitment and on patient retention. This would save money and time for biopharma companies, as well as speeding access to drugs for patients. Changes can range from understanding the issues in recruitment that go along with ethnicity, through changing criteria for enrolment, to considering the acceptability of the ingredients in the drugs, looking into the accessibility of the clinical trial centre for someone who can't afford a car, or considering the anxiety induced by not being familiar with a clinical trials site.
Making changes: Ethnicity
Race categorises people into groups sharing certain distinctive physical traits. Ethnicity is broader than race. It encompasses racial, national, tribal, religious, linguistic and cultural origins and background. Both ethnicity and race are social constructs, and neither are detectable in the human genome. [2, 5] Lack of representation in clinical research runs the risk of undermining clinical research and its goals. [2]
In an analysis of US clinical trials carried out between March 2000 and March 2020, fewer than half reported race or ethnicity data, and 80% of participants were white. [6] In an Ipsos UK survey published in 2024, significantly fewer respondents from ethnic minorities were willing to participate in clinical trials, compared with white respondents, and significantly more said that they were unwilling to participate. While ethnically minoritised adults are more likely to be invited to take part in a clinical trial, significantly fewer ...
(All Rights Reserved)