E156 Micro-Paper · Africa Clinical Trials

Distance-to-Trial-Site Burden

For the average rural African, the nearest clinical trial site may be hundreds o...

Africa Trials
3,515
US Trials
159,433
Gap Ratio
45x
Gini
0.732
The Gini coefficient of 0.732 indicates severe concentration, with most trials confined to a handful of nations.
Distance-to-Trial-Site Burden by Country Egypt: 11752 Algeria: N/A Morocco: 162 Tunisia: 540 Senegal: N/A Ghana: 261 Nigeria: 379 Cameroon: N/A DRC: N/A Ethiopia: 302 Kenya: 788 Uganda: 809 Tanzania: 460 Rwanda: N/A South Africa: 3654 Egy 11752 Sou 3654 Uga 809 Ken 788 Tun 540 162 11752
Distance-to-Trial-Site Burden Lorenz Curve 0% 0% 25% 25% 50% 50% 75% 75% 100% 100% Gini = 0.711
Burden vs Investment 50000 100000 150000 50000 100000 150000 Africa US Europe
No data
Research Profile Volume Growth Phase3 Complete Diversity Equity
Enrollment Distribution Africa Reference 10000 20000
Contribution Breakdown 11752 Egypt 3654 South Afri 809 Uganda 788 Kenya 540 Tunisia 2814 Others
Enrollment Density Africa Reference 10000 20000 30000 40000 50000
Why It Matters

For the average rural African, the nearest clinical trial site may be hundreds of kilometers away — a distance measured not in hours but in days of travel, multiple transport modes, and significant out-of-pocket costs.

In the spatial mapping of African clinical research, does the pattern of distance-to-trial-site burden 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 Gini coefficient of trial distribution as the primary estimand using registry metadata for each nation. The distribution yielded a Gini coefficient of 0.732 (95% CI 333.94-3326.24), 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.
Question

In the spatial mapping of African clinical research, does the pattern of distance-to-trial-site burden 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 Gini coefficient of trial distribution 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

94-3326.

Extra

24), 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.