Providing access to clinical trial results is also an ethical obligation, particularly out of respect for the trial participants (1,2). Since the early 2000s, a growing number of initiatives have sought to encourage – and later require – keeping clinical trial registries up to date on dedicated websites, and making trial results publicly available in those registries (3).

The 2014 European Clinical Trials Regulation stipulated that the main "raw" data from clinical trials (i.e. without author interpretation) be made available within a year of trial completion. Trial sponsors who fail to comply with this requirement are liable to fines (1,3). Yet in reality, this rarely occurs, and available data are glaringly sparse: for example, only 21% of the results from public-sector clinical trials completed in France in 2021 were made available in clinical trial registries within three years, while 69% of those from private-sector clinical trials were made available (4).

In France, public-sector clinical research in particular has a long track record of failing to report clinical trial data, but change may be on the horizon. A French cross-ministry report made several recommendations to clinical research stakeholders, aimed at rapidly improving this state of affairs. In response, the Greater Paris University Hospitals (AP-HP), for example, launched an initiative to publish all results from AP-HP-funded clinical trials in the European and US clinical trial registries (the Clinical Trial Information System [CTIS] and ClinicalTrials.gov, respectively) by 2028 (1). And the French National Institute of Health and Medical Research (INSERM) also acknowledged that it has room for improvement: only 40% of clinical trial results have been published or made available in clinical trial registries (5).

And what about going a step further and sharing clinical trial results with the very people who participate in those trials? While the idea is making headway, the fact remains that trial participants are far too often left out of the loop (6). How strange that people are inundated with legal information beforehand to encourage them to participate in a trial, yet they are not duly provided with the findings afterwards! Must we wait another 25 years before this becomes standard practice among researchers? In the meantime, this would mean continuing to overlook the fact that clinical trials are both dependent on and ultimately for the benefit of patients.

References 
1- Assistance Publique - Hôpitaux de Paris "Postage et publication des résultats" 16 September 2025: 15 pages.
2- "European clinical trials register: too few results reported" Prescrire Int 2020; 29 (219): 249.
3- French Ministries of Research and Health "Assurer le postage des résultats de tous les essais cliniques en France" May 2025: 83 pages. 
4- French Ministry of Research "Baromètre français de la Science Ouverte 2024" January 2025: 2 pages. 
5- "Être ou ne pas être… dans un registre d’essai clinique" 19 June 2025. pro.inserm.fr accessed 15 December 2025: 5 pages. 
6- Tai KH et al. "Open science must include effective results dissemination to study participants" PLoS Med 2025; 22 (10): e1004780: 4 pages.

 ©Prescrire 1 October 2026

Source: "Will clinical trial registries finally contain all results?" Prescrire Int 2026; 35 (285): 227. FREE.