If trials were distributed by population density, Nigeria (220M) should host far...
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
If trials were distributed by population density, Nigeria (220M) should host far more trials than Egypt (105M). The mismatch between population and trial density reveals that research access is determined by infrastructure rather than need.
The Evidence 130 words · target 156
In the spatial mapping of African clinical research, does the pattern of population density mismatch 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 Spearman rank correlation as the primary estimand using registry metadata for each nation. The distribution yielded a Gini coefficient of 0.732 (95% CI 333.40-3374.57), indicating severe concentration of trials among a small number of nations. Sensitivity analysis using Gini coefficient (0.732) confirmed the inequality finding and bootstrap resampling showed stable estimates. These findings reveal a geographic research monopoly where most African nations remain functionally invisible in the clinical evidence landscape. Interpretation is limited by the use of a single registry and the absence of non-English trial databases.
Sentence Structure
Question
In the spatial mapping of African clinical research, does the pattern of population density mismatch 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 Spearman rank correlation as the primary estimand using registry metadata for each nation.
Robustness
The distribution yielded a Gini coefficient of 0.
Interpretation
732 (95% CI 333.
Boundary
40-3374.
Extra
57), indicating severe concentration of trials among a small number of nations.
Extra
Sensitivity analysis using Gini coefficient (0.
Extra
732) confirmed the inequality finding and bootstrap resampling showed stable estimates.
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 the use of a single registry and the absence of non-English trial databases.