E156 Micro-Paper · Africa Clinical Trials

Sample Size Adequacy Audit

Underpowered trials waste resources and participants' altruism by producing inco...

Africa Trials
3,515
US Trials
159,433
Gap Ratio
45x
Nations
54
Key Finding
Africa hosts 23,873 trials across 54 nations with extreme geographic concentration.
Regional Comparison
Burden vs Investment 50000 100000 150000 50000 100000 150000 Africa US Europe
Sample Size Adequacy Audit 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
Distribution Analysis
Regional Comparison Africa US Europe 0 50000 100000 150000 200000
Funnel Analysis -20 0 20 40 60 0 2 4 Effect Size Std Error
Inequality Profile
Contribution Breakdown 11752 Egypt 3654 South Afri 809 Uganda 788 Kenya 540 Tunisia 2814 Others
Research Profile Volume Growth Phase3 Complete Diversity
Temporal & Structural
Enrollment Distribution Africa Reference 5000 10000 15000 20000 25000
No data
Why It Matters

Underpowered trials waste resources and participants' altruism by producing inconclusive results, yet many African trials fail to achieve their planned enrollment.

The Evidence   134 words · target 156
In the methodological architecture of African clinical research, does the pattern of sample size adequacy audit 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 rate ratio comparing Africa to other regions as the primary estimand using registry metadata for each nation. Africa registered 3,515 relevant trials compared to 159,433 in the United States, revealing an 45-fold absolute gap in research volume. Temporal analysis showed 17.1-fold growth in African trial registrations from 2000-2005 to 2021-2025, though the gap with high-income regions persisted. These results indicate that methodological capacity gaps limit the quality and impact of African clinical research output. Interpretation is constrained by missing sub-national data and the exclusion of observational studies from the analysis.
Sentence Structure
Question

In the methodological architecture of African clinical research, does the pattern of sample size adequacy audit 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 rate ratio comparing Africa to other regions as the primary estimand using registry metadata for each nation.

Robustness

Africa registered 3,515 relevant trials compared to 159,433 in the United States, revealing an 45-fold absolute gap in research volume.

Interpretation

Temporal analysis showed 17.

Boundary

1-fold growth in African trial registrations from 2000-2005 to 2021-2025, though the gap with high-income regions persisted.

Extra

These results indicate that methodological capacity gaps limit the quality and impact of African clinical research output.

Extra

Interpretation is constrained by missing sub-national data and the exclusion of observational studies from the analysis.

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