African Representation in Randomized Controlled Trials Published in Leading Medical and Cardiovascular Journals, 2019-2024

Clinical Snapshot

Key Findings

• P Value: Not reported

• Effect Size: 9.1% of general medical RCTs and 2.7% of cardiovascular RCTs included African sites in multicontinental studies

• Primary Outcome: African representation in RCTs: 3.9% Africa-only trials in general medical journals, 0.6% in cardiovascular journals

• Nnt Or Sensitivity: South Africa dominated representation; 75.9% of Africa-only trials focused on infectious diseases

• Confidence Interval: Not reported

Clinical Application

Findings highlight need for increased African participation in global trials and local research capacity building Relevant for Australian researchers conducting international trials and TGA/PBS decision-making regarding drug approvals based on predominantly non-African trial data Global clinical research community, particularly relevant for evidence-based medicine practitioners and guideline developers

Abstract

BACKGROUND: Despite accounting for a substantial proportion of the global population and disease burden, African countries are underrepresented in randomized controlled trials (RCTs), including those informing cardiovascular (CV) care. OBJECTIVES: In this study, we sought to quantify African representation in RCTs published from 2019 to 2024 in: 1) 5 leading general medical journals; and 2) 3 leading CV journals. METHODS: We conducted a systematic review of RCTs published from 2019 to 2024 in the British Medical Journal, the Journal of the American Medical Association, The Lancet, Nature Medicine, and the New England Journal of Medicine, and in Circulation, the European Heart Journal, and the Journal of the American College of Cardiology. Eligible studies included traditional, pragmatic, cluster, and stepped-wedge RCTs. African representation was assessed by trial scope (Africa-only vs multicontinental), country and regional participation, disease category, and African authorship. RESULTS: Among 2,138 RCTs published in leading general medical journals, only 83 (3.9%) were conducted exclusively in Africa, and 195 (9.1%) were multicontinental studies including at least 1 African site. In the CV journals, 2 out of 334 RCTs (0.6%) were conducted exclusively in Africa, and African sites were included in only 9 multicontinental trials (2.7%). South Africa accounted for the majority of Africa-based RCTs across both journal categories. Regionally, southern Africa predominated and central Africa was minimally represented. Trials published in general medical journals and conducted exclusively in Africa largely focused on infectious diseases (n = 63; 75.9%), with only 3 addressing cardiovascular disease (CVD). In contrast, Africa-including multicontinental trials more frequently investigated noncommunicable diseases, including CVD. African leadership was common in Africa-only trials but rare in multicontinental studies. CONCLUSIONS: African countries are profoundly underrepresented in RCTs published in the world's most influential medical and CV journals. Addressing this imbalance requires expanding African participation in global trials, investing in local research capacity, and promoting equitable leadership to strengthen the relevance and validity of clinical evidence. (Underrepresentation of African Countries in Randomized Controlled Trials: A Systematic Review of Leading General Medical and Cardiovascular Journals; CRD42024603157).

References

1. 1.Gaye, B., Morsy, M. I., Kitara, D. L., Singh, G., Shoaran, M., Gurgone, D., Seck, D., Alsaeed, A., Jobe, M., Carter, J., Gueye, K., Gaye, N. D., Ka, M. M., Jalloh, M. B., Liyong, E. A., Kengne, A. P., Lorenz, T., Guzik, T. J., Owolabi, M. O., Pellicori, P., Dzudie, A., Marijon, E., Preiss, D., Tshilolo, L., Fall, I. S., Pia Sattler, E. L., Ntusi, N. A. B., Seck, I., & Maffia, P. (2026). African representation in randomized controlled trials published in leading medical and cardiovascular journals, 2019-2024. Journal of the American College of Cardiology. https://doi.org/10.1016/j.jacc.2026.02.5097