The story of EHDEN

Let me tell you a story. A story of heroic people forging alliances by embarking on a remarkable Odyssey together in search of their very own holy grail. They had one noble goal: the harmonisation of a divided continent. It’s a story that would even make Homer jealous. It’s the story of EHDEN. No worries, no snakes, apples or naked people involved.


There once was a continent called Europe. No one can say for certain where this name originated from but one theory is that the continent was named after Europa, one of Zeus’ many lovers in the myths of their Greek ancestors. But this is a story for another time, let’s keep our focus. Europe was challenged with an ever increasing problem of a myriad of languages, systems and structures. Due to this problem, the people living within this continent were suffering. They were suffering because the people that were supposed to support them, clinicians, regulators, governments and the pharmaceutical industry had problems understanding their wellbeing, diseases, treatments, outcomes and the new therapeutics and devices they used. 

Until one day, as a deus ex machina, EHDEN arised. They decided to take matters into their own hands and forged an alliance with 11 public and 11 private partners. The public partners were led by Erasmus Medical Centre, the private partners by Janssen Pharmaceutica. Both were born and raised in the very heart of the continent, namely The Netherlands and Belgium. Together they combined forces to strive towards one common goal: to unite a divided continent by providing a new paradigm for the discovery, harmonisation and analysis of health data in Europe.


After many councils, they decided to embark on a journey together. An Odyssey (OHDSI) as they called it, again inspired by their Greek ancestors. In this Odyssey, they established another alliance with at its core a very powerful asset: the ‘Observational Medical Outcomes Partnership’ (OMOP) common data model (CDM) by OHDSI. A detailed story of OMOP CDM was already covered in a previous chapter. Thanks to this asset, EHDEN could develop a federated ecosystem of institutions generating clinical data in a standardized format. With researchers across academia and industry finally being able to speak a common language, they can create a network technology for research based on real-world clinical data.

EHDEN developed a federated ecosystem of institutions generating clinical data in a standardized format.


Although they found their holy grail faster than Jason and his Argonauts ever did, they still needed the support of strong local tribes across the continent to help them achieve their goals so they continued the journey. In their search they encountered, sharing the same vision and values. After a Spartan training (they did not want to involve just any tribe), EHDEN certified them as an official partner. will help the alliance in:

  • OMOP CDM ETL: Creating an Extraction Transform and Loading (ETL) pipeline to transform data from source to the OMOP CDM. This includes defining ETL specifications, local vocabulary mappings, coding and testing, etc.
  • OMOP Standardized vocabularies: Mapping local terminology systems to the Standardised Vocabularies.
  • Technical infrastructure Services: Commissioning of servers and databases, for example Postgresql, SQL Server, AWS Redshift.

EHDEN & you?

But there was yet one last piece of the puzzle missing in their quest. Someone quite important. Someone that could be you, the one reading this story. Even though EHDEN has now gathered more than 100 data partners, the door will always be open for others to join. This could be university or non-academic hospitals, primary care networks, existing registries, etc. So what brings EHDEN to the table? Besides a bag of golden coins to cover the costs which can be applied for by a series of open grant calls, EHDEN will also provide a transparent and fully reproducible research by standardizing both the health data and the analytical pipeline.

 The analytical code is sent to the data source, run locally in your own safe haven, and only the aggregated results are shared. In this way the original (patient-level) data remains at your site.

As a partner on this journey, you will be able to participate in studies along the way, performed in a federated manner. The analytical code is sent to the data source, run locally in your own safe haven, and only the aggregated results are shared. In this way the original (patient-level) data remains at your site. You remain in control of your own data and decisions about which study to participate in. The goal was to harmonise 100 million anonymised health records over five years across multiple hospitals and care networks. A target that has already exceeded more than 400 million!

So do you want to be part of this journey and do you feel like continuing this story with us? Reach out and let’s write the next chapter together! More info on the data partner calls to apply for funding can be found on the EHDEN website.

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Image adapted with the permission of the EHDEN project 

The EHDEN project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking (JU) under grant agreement No 806968. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA.