How long do research capabilities persist at African trial sites?
Africa Persistence
Low
Europe Persistence
High
Avg Site Lifespan
Short
Trials Audited
1,000
Key Finding
Africa grew from 678 trials in 2000-2005 to 11,599 in 2021-2025, a 17x increase, while the United States grew 2.9x over the same period.
Regional Comparison
Respiratory — Condition Analysis
Multi-Dimensional Equity Profile
Design Feature & Temporal Trend
Inequality Decomposition & Statistics
Respiratory — Computed Statistics
Africa: 1,886 | US: 17,385 | Europe: 15,924 | Ratio: 9.2x
Africa share: 5.4% | HHI4-region = 0.473 | Shannon H = 1.65 bits
Open Label: AF 1,545 vs US 23,963 (15.5x 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
Temporal persistence measures how long a research site maintains active trial capability over time. Low persistence means sites activate for single trials and then go dormant. In Africa, many sites exist only for the duration of one externally funded trial, creating a cycle of capacity build-up and collapse that wastes resources and institutional memory.
The Evidence 150 words · target 156
In the longitudinal analysis of research systems, has Africa's share of global clinical trials changed meaningfully over the past twenty-five years? This time-series audit tracked trial registration volumes across five epochs from 2000 to 2025 using ClinicalTrials.gov first-posted-date metadata for Africa (23,873 total) and comparator regions. Investigators reported the Africa-to-global volume ratio per epoch as the primary estimand for temporal persistence of research inequity. Africa grew from 678 trials in 2000-2005 to 11,599 in 2021-2025, a 17x increase, while the United States grew 2.9x over the same period. Despite this impressive absolute growth, Africa's share of global trials remained below six percent throughout all five epochs. The persistence of a stable volume ratio across two decades suggests a structural equilibrium maintained by systemic forces rather than a transient gap. These findings indicate that proportional equity requires policy intervention beyond organic growth. Interpretation is limited by retrospective registration of older trials.
Sentence Structure
Question
In the longitudinal analysis of research systems, has Africa's share of global clinical trials changed meaningfully over the past twenty-five years?
Dataset
This time-series audit tracked trial registration volumes across five epochs from 2000 to 2025 using ClinicalTrials.gov first-posted-date metadata for Africa (23,873 total) and comparator regions.
Method
Investigators reported the Africa-to-global volume ratio per epoch as the primary estimand for temporal persistence of research inequity.
Primary Result
Africa grew from 678 trials in 2000-2005 to 11,599 in 2021-2025, a 17x increase, while the United States grew 2.9x over the same period.
Robustness
Despite this impressive absolute growth, Africa's share of global trials remained below six percent throughout all five epochs.
Interpretation
The persistence of a stable volume ratio across two decades suggests a structural equilibrium maintained by systemic forces rather than a transient gap.
Boundary
These findings indicate that proportional equity requires policy intervention beyond organic growth.