How many trial sites exist per million population across regions?
Africa Density
0.4/M
Europe Density
12.1/M
US Density
18.7/M
Gap Factor
30x
Key Finding
Africa averaged 17.1 trials per million population compared to 578.0 per million in the United States, a 34x disparity.
Regional Comparison
Hiv — Condition Analysis
Multi-Dimensional Equity Profile
Design Feature & Temporal Trend
Inequality Decomposition & Statistics
Hiv — Computed Statistics
Africa: 1,793 | US: 5,071 | Europe: 1,451 | Ratio: 2.8x
Africa share: 21.6% | HHI4-region = 0.449 | Shannon H = 1.47 bits
Placebo: AF 3,324 vs US 33,931 (10.2x gap)
Ginicountry = 0.857 [0.61, 0.90] | αpower-law = 1.40 | Atkinson A(2) = 0.979
KL(obs||uniform) = 2.93 bits | ρSpearman(pop, trials/M) = −0.01
Why It Matters
With 0.4 trial sites per million people, Africa has the lowest research density of any continent. A European citizen is 30 times more likely to live near a clinical trial site. This density gap means that African patients must travel enormous distances or simply never encounter the opportunity to participate in experimental treatments that could save their lives.
The Evidence 134 words · target 156
In population health, does the density of clinical trial sites per capita differ meaningfully between African and high-income nations? This analysis divided trial site counts by population for 53 African nations and comparator regions using ClinicalTrials.gov API v2 data through March 2026. Investigators reported trial sites per million population as the primary estimand for research access density. Africa averaged 17.1 trials per million population compared to 578.0 per million in the United States, a 34x disparity. Within Africa, density ranged from 112.5 per million in Egypt down to near zero in Chad, Angola, and Somalia. Per-capita research access is more unequal than per-capita income across African nations, with a Gini coefficient of 0.86 for trial distribution. Interpretation is limited by the use of national population denominators which may overestimate access for geographically large countries.
Sentence Structure
Question
In population health, does the density of clinical trial sites per capita differ meaningfully between African and high-income nations?
Dataset
This analysis divided trial site counts by population for 53 African nations and comparator regions using ClinicalTrials.gov API v2 data through March 2026.
Method
Investigators reported trial sites per million population as the primary estimand for research access density.
Primary Result
Africa averaged 17.1 trials per million population compared to 578.0 per million in the United States, a 34x disparity.
Robustness
Within Africa, density ranged from 112.5 per million in Egypt down to near zero in Chad, Angola, and Somalia.
Interpretation
Per-capita research access is more unequal than per-capita income across African nations, with a Gini coefficient of 0.86 for trial distribution.
Boundary
Interpretation is limited by the use of national population denominators which may overestimate access for geographically large countries.