African representation in major clinical trials remains extremely limited, study finds

A new study co-led by the University of Glasgow and published in the JACC reveals that African countries remain severely underrepresented in randomized controlled trials (RCTs) published in the world's leading medical and cardiovascular journals.

Researchers analyzed 2,472 randomized controlled trials published between 2019 and 2024 across eight major journals and found that only 3.9% of trials in leading general medical journals were conducted exclusively in Africa, while just 0.6% of trials in major cardiovascular journals were Africa-only studies.

Africa bears roughly 25% of the global disease burden, yet African populations are rarely included in studies that shape international medical guidelines. The study also found that African sites were included in only a small proportion of multicontinental trials, and African leadership was uncommon in these studies.

"Our analysis highlights a profound imbalance in the global clinical research landscape," said Dr. Bamba Gaye, of the Alliance for Medical Research in Africa and Cheikh Anta Diop University in Dakar, Senegal. "Populations across Africa remain largely excluded from trials that guide clinical practice worldwide."

The study also identified regional disparities within the continent. South Africa accounted for the majority of Africa-based trials, while large parts of central Africa had little or no representation.

Most trials conducted exclusively in Africa focused on infectious diseases, while noncommunicable diseases, including cardiovascular disease, were underrepresented, despite their rapidly increasing burden on the continent.

"Clinical trials underpin evidence-based medicine," said Professor Pasquale Maffia, of the University of Glasgow, UK. "If African populations are not adequately represented, global medical evidence risks being incomplete."

The authors call for greater investment in African research infrastructure, funding for locally led studies, and stronger international collaborations to ensure global clinical research reflects the diversity of the world's populations.

The systematic review evaluated randomized controlled trials published between 2019 and 2024 in leading journals including The New England Journal of Medicine, The Lancet, JAMA, Nature Medicine, BMJ, Circulation, European Heart Journal, and the Journal of the American College of Cardiology. In total, 2,472 eligible trials were analyzed to assess geographic representation, disease focus, and authorship patterns.

More information:
Bamba Gaye et al, African Representation in Randomized Controlled Trials Published in Leading Medical and Cardiovascular Journals, 2019-2024, JACC (2026). DOI: 10.1016/j.jacc.2026.02.5097

Provided by University of Glasgow