Non-reporting of clinical trial results is an ongoing global public health problem.

The best currently available evidence shows that around half of all trials go unreported: this means that doctors and patients see only a partial, biased fraction of the true evidence. We cannot make informed decisions about treatments unless all the data is reported. Under EU rules, from December 2016, all trials on the European Union Clinical Trials Register (EUCTR) should post results within 12 months of completion. There has never been a rule as simple and clear as this, anywhere in the world. Our EU Trials Tracker shows which organisations are compliant, and which aren't. Our paper in the BMJ analysed the data as of January 2018, and found that only 49% of Europe's clinical trials reported results in the register.

This website is one of a series of Trials Trackers produced by the Bennett Institute for Applied Data Science at the University of Oxford.

What is a Clinical Trial?

Clinical trials are the gold standard in medicine: they are the most fair test of whether a treatment really works; they are also used to assess how one treatment compares to other available options. In a clinical trial, the treatment is usually given to real patients, in a real-world setting. The outcomes measured are ideally real-world problems that matter to patients, such as pain, disability or death; but can also include lab tests, or scans.

Why Do We Need All Trials Reported?

We use the results of clinical trials to make real-world decisions about which treatments work best. We can’t make informed choices if the results of clinical trials are withheld from doctors, researchers, and patients. Read more about this from the AllTrials Campaign.

Have You Published Anything About This?

Yes! You can read our full paper including further statistical analyses, technical details regarding our methods, and a longer discussion of the background and implications of this work in The BMJ


Goldacre B, DeVito NJ, Heneghan C, et al. Compliance with requirement to report results on the EU Clinical Trials Register: cohort study and web resource. BMJ 2018;362:k3218.

Who Made the EU Trials Tracker?

The Bennett Institute for Applied Data Science at the University of Oxford: we are a truly multi-disciplinary team of clinicians, academics, and software engineers working together to make data more impactful in the real world. Francis Irving and Seb Bacon were the software engineers for the site; Ben Goldacre was the principal investigator; Nick DeVito was the researcher; with contributions from the Bennett Institute team and Open Knowledge International.

How Do We Contact You?

Email us! [email protected]. We'd particularly like to hear about any errors, omissions or ideas.

When Was The Data Last Updated?

This data updates regularly, on a monthly cycle. We think it’s important that information about who is reporting clinical trials is current and regularly updated: so that sponsors are always motivated to improve; and sponsors who do improve can see their good work reflected in public. The current data was taken from the register starting on 2024-05-04. All clinical trials on medicinal products (drugs and vaccines) conducted in Europe since 2004 are in the register. For full details, see the register's about page.

What Does “Due” Mean?

When more than a year has passed since the completion of a trial, the results should be published, and we call it "due". Specifically, we take the latest “global end of trial date” listed for the trial; then add a year (the maximum delay permitted for sponsors to report results); and finally add 4 weeks (the statutory maximum 15 days administrative delay for results to be published on the register by the regulator, and another 5 days to allow for national holidays and exceptional circumstances). Currently, any trial completed earlier than 2023-04-06T00:00:00 is due. You can read a detailed description of the way we assess an individual trial here

What’s a Major Sponsor?

The initial table on the front page shows only sponsors with 50 or more total trials in the register. This is to make the headline rankings more easily viewable. If you click “all sponsors” you can see all sponsors! This is a list of thousands, so we have also made a search box where you can find a sponsor you are particularly interested in.

What does “Inconsistent Data” Mean for a Trial?

“Inconsistent Data” means that we cannot definitively say the trial is due to report with the data provided on the EUCTR. This could be for any number of reasons involving the sponsor (for not providing timely and accurate information), national competent authorities (for failing to quality control submissions or update entries), and/or the design and implementation of the EUCTR itself:

Currently, we identify the following issues:

  1. A trial in which all sites are either “completed” or “terminated” but no “Date of the global end of the trial” is provided. The results page of a trial may also contain a “global trial end date” field however this is not currently included in our analysis as it is unclear how this date is provided and quality controlled. Information provided in the country protocols, including the “Date of the global end of the trial,” must first pass through a national competent authority.
  2. A trial has a “Date of the global end of the trial” listed, however the trial is still listed as “Ongoing” in at least 1 country. As the name suggests, the “Date of the global end of the trial” field is supposed to only be used once the trial has completed globally, and match for all country protocols. Unfortunately, this is often not the case.
  3. For certain trials, a protocol or protocols will have no trial status. While this can occur for protocols in EU countries (Examples here and here), this will always occur when a trial includes a protocol for the “Outside EU/EEA” portion of the trial (Examples here and here). According to the EUCTR, these protocols are “linked to European paediatric-medicine development” and due to limitations of the EUCTR, never display a trial status. We have tags to separately indicate “No Trial Status on Register” and when a trial contains an “Outside EU/EEA” protocol.

While we cannot accurately assess the status of these trials, they may still have results. We note this in the label next to the trials. When the fault lies with the sponsor, we think the EU registry managers could and should automatically identify trials with inconsistent data, as we have done; and then require sponsors to correct their records.

What Does Terminated Mean? What if my Trial Never Started?

We have included a tag to identify when trials are “Terminated” for all locations (called “Prematurely Ended” on EUCTR). A trial that ends early, but enrolled and collected data on patients, is required to report results under EU Guidelines. In some instances trials are registered on the EUCTR but are withdrawn before starting enrollment, and therefore have no data to report. The EUCTR has no reliable way to show that a trial never started, however sponsors may be able to use workarounds to ensure these trials show up as properly reported. If the trial ended prior to July 2013, you should have the ability to upload a statement that the trial never began and satisfy the reporting requirement. For trials that ended after July 2013, you may be able to combine a statement with "null" codes for the required areas. An example of this is available here. For more details on this see Jackie Pullen's presentation from the QUEST Clinical Trials Workshop 2019 from the links here. We will continue to evaluate terminated trials as due to report, so as not to miss legitimate trials due to report, and those “Terminated” for all locations will have a tag denoting this. We hope to be able to exempt these trials from the tracking statistics entirely once the EUCTR system is improved to better handle this issue.

What Does Exempt Mean?

Some trials in our “Not Due” category would never become due because they are identified as a Phase 1 trial that is not part of a Paediatric Investigation Plan. These types of trials are not covered by the reporting guideline and are typically not made public on the EUCTR. However, some trials meeting this description are available on the EUCTR. There may be some reason why these trials are made public and required to report, however to remain conservative, we now identify these trials as “Exempt” and they remain in the “Not Due” category.

Over time organisations can merge, change names, or split: companies may acquire other companies; universities may join together; and so on. If we think an organisation is now effectively part of another, we say so at the bottom of its page. Conversely, if an organisation now effectively includes other organisations, and so is responsible for their trials, we list those at the bottom of its page. The trials of the smaller organisations are not included in the counts of the larger one. We've made every effort to get these relationships right; there is no canonical data source on mergers and acquisitions; if you think we should update any of our data on this, please tell us.

What is the impact of Brexit?

Due to Brexit, as of 1 January 2021, new trials from the UK will no longer be registered on the EUCTR. Any UK protocols that were in "Ongoing" status as of the end of 2020 are now locked in the status "GB - no longer in EU/EEA" and can no longer be updated. This means ongoing trials registered exclusively in the UK will never have completion data appear. While sponsors may still upload results, we will not be able to reliably assess the due date of these trials. For trials registered in more than one location that include the UK, we will ignore the UK protocols in status "GB - no longer in EU/EEA" when determining if a trial is complete or not. As of January 2021, this has not yet been implemented but we are working to adjust our code to incorporate these changes as soon as possible. When this is implemented, some "Not Due - Ongoing" trials will move into the "Due" category if the only outstanding uncompleted trial is a UK trial. We expect this will effect a relatively small number of trials and no assessments of currently due trials should be impacted due to Brexit.