Capital cities monopolize African clinical trial infrastructure because they hos...
Africa Trials
3,515
US Trials
159,433
Gap Ratio
45x
Gini
0.732
Key Finding
The Gini coefficient of 0.732 indicates severe concentration, with most trials confined to a handful of nations.
Regional Comparison
Distribution Analysis
Inequality Profile
Temporal & Structural
Why It Matters
Capital cities monopolize African clinical trial infrastructure because they host the major teaching hospitals, have reliable electricity and internet, and offer the transport links that sponsors require for monitoring.
The Evidence 129 words · target 156
In the spatial mapping of African clinical research, does the pattern of capital city monopoly index reveal structural inequity in African research investment? This cross-sectional audit evaluated 23,873 African and 190,644 United States interventional trials registered on ClinicalTrials.gov through April 2026. Investigators computed the Herfindahl-Hirschman concentration index as the primary estimand using registry metadata for each nation. The distribution yielded a Gini coefficient of 0.732 (95% CI 326.74-3379.91), indicating severe concentration of trials among a small number of nations. The Herfindahl-Hirschman index reached 3472.872, exceeding the threshold of 0.25 that indicates a highly concentrated distribution. These findings reveal a geographic research monopoly where most African nations remain functionally invisible in the clinical evidence landscape. Interpretation is limited by reliance on ClinicalTrials.gov alone, which may undercount locally registered African studies.
Sentence Structure
Question
In the spatial mapping of African clinical research, does the pattern of capital city monopoly index reveal structural inequity in African research investment?
Dataset
This cross-sectional audit evaluated 23,873 African and 190,644 United States interventional trials registered on ClinicalTrials.
Method
gov through April 2026.
Primary Result
Investigators computed the Herfindahl-Hirschman concentration index as the primary estimand using registry metadata for each nation.
Robustness
The distribution yielded a Gini coefficient of 0.
Interpretation
732 (95% CI 326.
Boundary
74-3379.
Extra
91), indicating severe concentration of trials among a small number of nations.
Extra
The Herfindahl-Hirschman index reached 3472.
Extra
872, exceeding the threshold of 0.
Extra
25 that indicates a highly concentrated distribution.
Extra
These findings reveal a geographic research monopoly where most African nations remain functionally invisible in the clinical evidence landscape.
Extra
Interpretation is limited by reliance on ClinicalTrials.
Extra
gov alone, which may undercount locally registered African studies.