A Secure Data Environment (SDE) is a controlled system where health data is stored and accessed safely for research and analysis. Instead of sharing data directly with researchers or organisations, the data stays within the secure environment, and approved users access it under strict security rules. 

Key points about Secure Data Environments: 

• Data does not leave the environment – researchers work within the system rather than receiving copies of the data.
• Data is de-identified before access – this means personal information is removed or obscured to protect privacy. 
• Strict security controls – only approved users can access the data, and their activity is monitored.
• Used for research, planning, and improving healthcare – the data helps scientists and policymakers make better decisions about health.

These environments are designed to protect patient information while allowing important research that can improve healthcare for everyone​.  

More information can be found on the Understand Patient Data website along with other resources.