Trends in clinical trial registration in sub-Saharan Africa between 2010 and 2020: a cross-sectional review of three clinical trial registries

OBJECTIVE: Prospective registration of clinical trials is an ethical, scientific, and legal requirement that serves several functions, including minimising research wastage and publication bias. Sub-Saharan Africa (SSA) is increasingly hosting clinical trials over the past few years, and there is limited literature on trends in clinical trial registration and reporting in SSA. Therefore, we set out to determine the trends in clinical trials registered in SSA countries between 2010 and July 2020. METHODS: A cross-sectional study design was used to describe the type of clinical trials that are conducted in SSA from 1 January 2010 to 31 July 2020. The registries searched were ClinicalTrials.gov (CTG), the Pan African Clinical Trials Register (PACTR), and the International Standard Randomized Controlled Trial Number (ISRCTN). Data were extracted into Excel and imported into STATA for descriptive analysis. RESULTS: CTG had the highest number of registered trials at 2622, followed by PACTR with 1501 and ISRCTN with 507 trials. Trials were observed to increase gradually from 2010 and peaked at 2018–2019. Randomised trials were the commonest type, accounting for at least 80% across the three registries. Phase three trials investigating drugs targeted at infections/infestations were the majority. Few completed trials had their results posted: 58% in ISRCTN and 16.5% in CTG, thus suggesting reporting bias. CONCLUSION: Despite the gradual increase in clinical trials registered during the period, recent trends suggest a drop in the number of trials registered across the region. Strengthening national and regional regulatory capacity will improve clinical trial registration and minimise reporting bias in completed clinical trials. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05423-1.