The Observational Health Data Sciences and Informatics (or OHDSI, pronounced "Odyssey") network is a multi-stakeholder, interdisciplinary collaborative to bring out the value of health data through large-scale analytics.

OHDSI aims to generate accurate, reproducible, and well-calibrated evidence and promote better health decisions and better care.

OHDSI Europe is led by the coordinating center embedded in the Health Data Science Group of the Erasmus University Medical Center in Rotterdam, The Netherlands.

It builds a strong European OHDSI community that actively contributes to the further extension of the OMOP CDM and analytical tool development.

EHDEN was launched in November 2018 to address the challenges of generating insights and evidence from real-world clinical data at scale – supporting patients, clinicians, payers, regulators, governments and industry. The OMOP Common Data Model is at the heart of EHDEN.

It has enabled large-scale, privacy-preserving research through a common framework, accelerating real-world evidence generation and establishing Europe as a global leader in federated health data science and infrastructure.

The Data Analysis and Real World Interrogation Network (DARWIN EU®) is the coordination centre established by the European Medicines Agency (EMA) and the European Medicines Regulatory Network to provide timely and reliable evidence on the use, safety and effectiveness of medicines, including vaccines, from real-world healthcare databases across the EU.

It has created a permanent federated network of real-world health data standardised to the OMOP Common Data Model, and has already delivered studies supporting regulatory decisions on drug safety, effectiveness and disease epidemiology.