Investigation of the publication rate of recent research projects using non-human primates in France

The use of non-human primates (NHPs) in biomedical research entails significant ethical considerations, demanding careful evaluation of both scientific necessity and research outcomes. This study presents a retrospective literature review comparing non-technical summaries (NTS) of research projects authorized in France between 2016 and mid-2019 with corresponding peer-reviewed scientific publications. The primary objective was to assess the publication rate of NHP-based projects, with secondary outcomes including time to publication, discrepancy in animal use reporting, and the scientific impact of published results. Literature searches were conducted primarily via PubMed, supplemented with additional methods such as author-based searches. Out of 191 projects analyzed, 56% led to at least one publication, the publication rate varying markedly, ranging from 83% in ophthalmology to 30% in immunology. In most cases, publications reported fewer animals than originally authorized: 1,751 actually used out of the 3,649 planned. 2,421 animals had been authorized for the projects for which no publication could be identified. The overall median Relative Citation Ratio (RCR), representing the field- and time-normalized citation rate for published studies, was 1.1, indicating a moderate scientific impact. These findings highlight the need for greater transparency in reporting, including the publication of negative or inconclusive results. The study underscores the importance of systematic retrospective assessments, improved harm/benefit evaluations under the EU Directive, and stronger upstream review mechanisms. Key recommendations include pre-registration of studies, mandated publication of all research outcomes, and the development of open-access platforms to facilitate data sharing, reduce unnecessary duplication, and enhance both ethical and scientific value.