A new Cohort Discovery Service is coming soon

We’re excited to announce that HDR UK will be launching a new improved Cohort Discovery Service on the 14th of April 2026. 

The new site has been designed with users in mind, featuring an intuitive natural language query builder and clear guidance to help you get started quickly. As an open-source service, it is also available for use and adaptation by the wider research community, and we will be driving forward with new features and innovation of the discovery service. 

Please note that existing queries will not be migrated to the new service. We recommend saving any queries or search terms you wish to retain so you can rerun them after launch. 

About Cohort Discovery

Cohort Discovery helps researchers and innovators to rapidly determine the size of the population which may be relevant to their research question within different datasets, without having to directly contact the individual organisations that hold the data.  

Users can specify defined characteristics relevant to their proposed analysis (e.g. the number of female asthmatics between the ages of 25 and 35) through the Cohort Discovery user interface. These search terms are then sent as a real-time query to multiple pseudonymised datasets across multiple Data Custodians, with results returned in the form of a numerical count of individuals that meet those specific criteria. 

Researchers can then understand whether a dataset contains a cohort (or group) of interest and if so, contact the Data Custodian to find out more or submit a Data Access Request. The Gateway enables researchers and innovators to easily submit standardised requests to multiple custodians identified through Cohort Discovery. This saves time and effort for both the researcher and the Data Custodian.