Ethnic minority representation in UK COVID-19 trials: systematic review and meta-analysis

Abstract

Background The COVID-19 pandemic has highlighted health disparities affecting ethnic minority communities. There is growing concern about the lack of diversity in clinical trials. This study aimed to assess the representation of ethnic groups in UK-based COVID-19 randomised controlled trials (RCTs). Methods A systematic review and meta-analysis were undertaken. A search strategy was developed for MEDLINE (Ovid) and Google Scholar (1st January 2020–4th May 2022). Prospective COVID-19 RCTs for vaccines or therapeutics that reported UK data separately with a minimum of 50 participants were eligible. Search results were independently screened, and data extracted into proforma. Percentage of ethnic groups at all trial stages was mapped against Office of National Statistics (ONS) statistics. Post hoc DerSimonian-Laird random-effects meta-analysis of percentages and a meta-regression assessing recruitment over time were conducted. Due to the nature of the review question, risk of bias was not assessed. Data analysis was conducted in Stata v17.0. A protocol was registered (PROSPERO CRD42021244185). Results In total, 5319 articles were identified; 30 studies were included, with 118,912 participants. Enrolment to trials was the only stage consistently reported (17 trials). Meta-analysis showed significant heterogeneity across studies, in relation to census-expected proportions at study enrolment. All ethnic groups, apart from Other (1.7% [95% CI 1.1–2.8%] vs ONS 1%) were represented to a lesser extent than ONS statistics, most marked in Black (1% [0.6–1.5%] vs 3.3%) and Asian (5.8% [4.4–7.6%] vs 7.5%) groups, but also apparent in White (84.8% [81.6–87.5%] vs 86%) and Mixed 1.6% [1.2–2.1%] vs 2.2%) groups. Meta-regression showed recruitment of Black participants increased over time (p = 0.009). Conclusions Asian, Black and Mixed ethnic groups are under-represented or incorrectly classified in UK COVID-19 RCTs. Reporting by ethnicity lacks consistency and transparency. Under-representation in clinical trials occurs at multiple levels and requires complex solutions, which should be considered throughout trial conduct. These findings may not apply outside of the UK setting.

Representativeness in health research studies: an audit of Greater Manchester Clinical Research Network studies between 2016 and 2021

“…UK research may have a particular problem. Authors of a recent systematic review of the representativeness of 30 UK COVID vaccine trials reported limited and opaque reporting of participant ethnicity, similar to that found here, meaning it was difficult to be certain to what extent Asian, Black, Mixed and other ethnic minority groups were underrepresented in these trials [ 19 ].…”

Health and social care experience and research perception of different ethnic minority populations in the East Midlands, United Kingdom (REPRESENT study)

“… 6 , 41 However, evidence has also shown that the involvement of ethnic minority groups through different stages of the research trials is inconsistent. 2 A review of clinical trials shows that most studies do not report data on research inclusion approaches, screening, follow‐up or outcome effect estimates of a specific ethnicity. 12 , 42 , 43 Factors that have limited ethnic minority representation in research have included stereotypical and negative attitudes of researchers, language skills, lack of knowledge of the study and research processes, relevance of research and study protocol, time, resource constraints (e.g., travel costs), lack of diversity within the research team and inadequate housing or transport.…”

“… 1 These disparities in health research were particularly highlighted in the recent COVID‐19 pandemic, which disproportionately affected vulnerable and marginalised populations, including ethnic minorities in the United Kingdom; however, representation of these groups in clinical trials was significantly low. 2 Similarly, poor ethnic minority representation has been observed in several other health research areas, including cancer, diabetes and cardiovascular disease. 3 , 4 , 5 , 6 The consequence of this is that medical and social care research, which informs guideline recommendations and everyday clinical practice, is less generalisable and applicable to ethnic minority populations.…”

Vietnamese Americans' level of trust in sources of information and willingness to participate in COVID-19 clinical trials

“…As researchers raced to develop vaccines and treatments for this new infectious disease, historically marginalized communities were inadequately represented in COVID-19 clinical trials [4][5][6]. However, increased participation of racial and ethnic minorities is essential for understanding diseases, preventive factors, and treatment effectiveness across populations.…”