# The Global Cognitive Deficit

In the epistemology of medical evidence, does the exclusion of African populations from clinical trials create a global cognitive deficit that weakens the universal validity of biomedical knowledge? This meta-epidemiological analysis compared Africa's population share (18% of 8 billion) to its trial share (5.9% of major-registry trials) using ClinicalTrials.gov data for 23,873 African trials. Investigators computed the population-to-trial ratio as the primary estimand for evidence representativeness. Africa contributes 18% of the world's population but only 5.9% of major-registry clinical trials, creating a 3x representation deficit. Unique African phenotypes including sickle cell disease (101 trials), peripartum cardiomyopathy (4 trials), and rheumatic heart disease (23 trials) remain severely understudied. The absence of Africa from the evidence base does not merely disadvantage Africans but weakens the scientific validity of findings presumed to be universal. Interpretation is limited by the exclusion of non-ClinicalTrials.gov registries and observational studies.

## References

1. Sirugo G, et al. "The missing diversity in human genetic studies." Cell. 2019;177:26-31.
2. Lang T, Siribaddana S. "Clinical trials have gone global: is this a good thing?" PLoS Med. 2012;9:e1001228.

## Note Block

- Type: research
- App: https://mahmood726-cyber.github.io/africa-e156-students/health-disease/dashboards/cognitive-deficit.html
- Code: https://github.com/mahmood726-cyber/africa-e156-students/blob/master/health-disease/code/cognitive-deficit.py
- Data: ClinicalTrials.gov API v2
- Date: 2026-04-05