Getting started

Accessing clinical trial data is a process that requires, as an important preliminary step, establishing what types of data (or documents) you are interested in and the correct party to request them from.

Types of data

Any given study will produce many types of clinical trial data, from case report forms to electronic individual participant data, clinical study reports, journal publications, and registry entries (to name just some of the many). Note that not all trials produce all types of documents/data. For example, clinical study reports are almost exclusively produced for regulatory purposes, therefore generally do not exist for trials of non-regulated interventions (such as a surgical techniques or behavioral interventions).

When you set out to obtain clinical trial data, it helps you and the data holder to be clear just what kind of data you’re hoping to obtain. Perhaps one type (e.g. a clinical study report) is all you need. Perhaps you need two types. Or perhaps you need every type that possibly exists.

The right party from which to request the data

There are four broad categories of parties that hold data: investigators, sponsors, regulators and to some extent, public repositories.

  • Investigators. If a trial is published, asking for data from the authors of the trial publication is an easy first step (but be prepared that this may not result in data).
  • Funders and sponsors. Several governmental funding bodies and many pharmaceutical companies have created platforms for sharing data from clinical trials they funded. The National Institutes of Health (NIH) has a platform dedicated to data shared from a number of its institutes.   
  • Regulators.  Health Canada posts clinical trial data to its website and it can be freely downloaded by anybody around the world. Other regulators, chiefly EMA, require requests for documents of compounds regulated prior to January 1, 2015 but EMA is prospectively making more recent data available through its Clinical Data Publication website. FDA medical, statistical, and other reviews that discuss trials submitted to them, are easily accessible from Drugs@FDA. Our Regulatory Resources page explains the types of data regulators hold, and how you can obtain them.
  • Public repositories such as Zenodo and Dryad are freely accessible, but searching them for clinical trial data is not easy because they are large repositories that contain many other types of documents. The Drug Industry Documents archive (widely known as DIDA) also holds a selection of clinical study reports, formerly confidential internal memoranda, and other trial data.
  • Third-party initiatives such as the Yale University Open Data Access (YODA) Project and Vivli Center for Global Clinical Research Data host clinical trial data on behalf of industry. IPD may be released into a central repository with access overseen by an independent entity that reviews data requests and grants approvals. 

Requesting data

Some entities which hold data (e.g. the GSK Study Register, Health Canada’s portal for clinical trial data, and EMA’s Clinical Data Publication website) may not require a request; you can download documents directly from the website, including clinical study reports.

But for much clinical trial data that is not publicly available, requests are necessary. Once you have established what type of data you wish to obtain and the correct party (or parties) to request data, the next step is to request it.

  • Funders and Sponsors: Each of the web-based data sources has its own procedure for requesting data which is described on the relevant website.  We have compiled a list of industry sponsors and instructions for requesting data from each. Some sponsors maintain their own public register (e.g. GSK and Merck) where they post some trial documents. (In at least one case – GSK – redacted clinical study reports are also posted.) Many sponsors have established a process for third party requests for data.  Some companies manage this process themselves, while others use a consortia model such as ClinicalStudyDataRequest.com (CSDR) and Vivli. Typically, the data on offer are clinical study reports and electronic individual participant data. Generally, requestors must submit a research proposal for review before being granted access to data. All sponsors have limitations on data release that are generally enforced by requiring requestors to sign a Data Use Agreement (DUA) prior to data access. Most sponsors do not directly release data even following an approved request for data and signed DUA. Instead, access to data is granted through a secure web-based portal.
  • Regulators: All major regulators – US FDA, EMA, Health Canada, Japan PMDA, and Australia’s Therapeutic Goods Administration make regulatory data available.  Which data, however, differs greatly, as do the terms of access–for example, some (e.g. Australia’s TGA) only makes the regulators’ evaluation reports available while others (e.g. Health Canada and the EMA) are proactively publishing clinical trial data to their website. See our Regulatory Resources page for details.

If you know of a novel source of clinical trial data not listed here, be sure to drop us a line, even if you are not sure whether we are aware of it. We will share it with the community.