Enhancing global clinical trial transparency for better health outcomes for all 

Regulatory and legislative gaps

Our analysis ( Table 1) of clinical trial regulations identified from 94 countries observed that, despite regional variation, 75 of 94 countries’ national regulatory frameworks cover 9 or more of 11 key components of clinical trial conduct and governance. International guidelines, such as Declaration of Helsinki and The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), are commonly referenced, and research ethics committee approval and informed consent from trial participants are universally required by national guidelines.

However, the review revealed a lack of governmental requirements for public registration of clinical trials and reporting of trial results in many countries. Two-thirds (66%) of the 94 countries require prospectively registering all clinical trials in a public registry prior to enrolling participants, while 40% have mandates for public reporting of trial findings—two critical mechanisms to promote transparency and increase the value of trials. Furthermore, disparities in governmental guidance are seen between high-income countries (N = 44) and low-income countries (N = 12), in particular on explicit privacy protections (100% vs. 58%), trial registration (80% vs. 25%), and reporting of trial results in registries (66% vs. 0%).

Institutional capacity disparity

Between 2018 and 2022, about half of the 340,397 trials in WHO International Clinical Trial Registry Platform (ICTRP), were recruiting participants in high-income countries (HICs), with the highest number of recruitments in the United States ( Figure 1). China and India saw fast-growing clinical trial activity, being 2nd and 3rd among the top 10 countries by the total number of trials registered, the others being HICs in North America, Europe, and Japan ( Figure 2). Low-income countries accounted for less than 1% of total clinical trials worldwide, which is disproportionate to their high disease burden. The numbers of clinical trials, sponsored by entities other than commercial companies or individuals [1], are disproportionately lower in WHO’s African region and South-eastern Asian region, compared to other regions ( Figure 3). This indicates that clinical trials for non-commercial purposes face particular challenges in low- and middle-income regions (LMIC).

Figure 1. Distribution of clinical trials registered in high-income (HI), upper-middle-income (UMI), lower-middle-income (LMI) and low-income (LI) countries between 2018 and 2022 (data extracted from ICTRP).

Figure 2. Top 10 countries of recruitment between 2018 and 2022 in ICTRP.

Figure 3. Number of clinical trials sponsored by non-commercial entities (i.e., not companies or individuals) in each WHO region (2018-2022).

Research funding inequity

Based on data of 4829 trials (approximately 1%) registered between January 2018 and December 2022, whose funding information could be traced in World RePORT,³ the WHO Americas region accounts for 77% of clinical trial funding, reflecting a stark imbalance in the global distribution of clinical research funding relative to the population size and gross domestic product (GDP). The National Institutes of Health in the United States of America, European Commission, European and Developing Countries Clinical Trials Partnership, Wellcome Trust and Bill and Melinda Gates Foundation were the largest funders of clinical trials.³ Furthermore, the lack of transparency in funding sources - reflected by the very low percentage of registered trials that could be linked to a grant number in the World RePORT, reveals a gap in clinical trial oversight and public reporting, that could hinder funding coordination and exacerbate inequities in clinical trial capability and infrastructure.

Barriers to mapping the global clinical trial landscape

The rapid reviews highlight significant gaps in the availability and accessibility of information about the global clinical trial landscape. Better completeness and quality of data would facilitate a better understanding of regional disparities and areas for improvement.

A substantial proportion of government documents, particularly in low- and middle-income countries, were either unavailable online or accessible only in local languages—not only limiting their utility in informing global mapping initiatives, but also hindering cross-border knowledge-sharing and opportunities for increased international collaboration and investment.

Clinical trial registry records also often lacked consistency and completeness in data quality as well as a lack of harmonization in the way data are collected both between and within registries. This makes aggregation challenging. Additionally, some registries do not support requests for bulk data access or do not support automated data extraction, further constraining the potential for summary analyses. These limitations are compounded by inconsistencies in regulatory requirements regarding the public registration of trials before they begin and the reporting of results after trial completion.

Furthermore, it is difficult to analyse fragmented datasets that include free-text data fields, different names for the same sponsor, and incomplete reporting on data components such as recruitment sites and funding sources. Limited curation and oversight of data entry processes further compromise data quality. For instance, deduplication of trials registered across multiple platforms is hindered by inconsistencies in trial identifiers, sponsor names and other data inconsistencies. Similarly, noncompliance with WHO’s international standards for trial registration and results reporting reduces the completeness and accuracy of data available for global analyses of the trial landscape.^4–6

Such barriers undermine efforts to establish equitable representation of trial activity, particularly in underrepresented regions and resource-constrained settings. These issues not only obscure insights into the true scale and distribution of clinical trials, but also hinder efforts to improve transparency, accountability, and ethical standards in clinical research worldwide.