Sample Size Adequacy Audit

Abstract

Within the context of African clinical research methodologies, does the pattern of sample-size audits reveal underlying disparities in research investment across the continent? This cross-sectional review analysed 23,873 African and 190,644 US interventional trials registered on ClinicalTrials.gov up to April 2026. Investigators calculated the rate ratio comparing Africa to other regions, using each country's registry data as the primary measure. Africa registered 3,515 pertinent trials, whereas the United States registered 159,433, indicating a forty-fivefold difference in research volume. Nonetheless, from 2000-2005 to 2021-2025, trial registrations in Africa increased by a factor of 17.1; however, the disparity with high-income regions persisted. These findings imply that deficiencies in methodological capacity impede the quality and impact of African clinical research. Limitations of the study include missing sub-national data and the exclusion of observational studies from the analysis.