Health data has the power to save lives – but only if it represents all of us.
Richard Dale, Chair of the OneLondon Data Board, explains how the London Secure Data Environment will help make research more inclusive and impactful for London’s diverse communities (14 November 2025)
Next week we are really excited to be hosting an event, with representatives from across the NHS, government, academics, clinicians, and members of the public, to make some really important announcements about how we in London are making changes to better use data to drive research, innovation, and ultimately, health care in the Capital.
The partnership, called Health Data for London, that we will be announcing, will mean that, for the first time, there will be a genuinely connected data landscape across London, with anonymised data brought together from hundreds of GP practices, together with that from mental health, community and acute NHS service providers.
I may well be posting more about this in coming weeks and months (and beyond!) as it’s a subject I am passionate about.
But, it’s hugely complex, and I recognise not everyone shares my levels of interest, so I wanted to pull out some of the reasons I’m passionate about this work.
In this particular blog, I want to focus on why London’s SDE is a vital tool to tackle health inequalities and improve outcomes for people in every community in London.
What’s a Secure Data Environment?
The work we are already driving forward, and which will be accelerated by Health Data for London, is based on something called a Secure Data Environment (SDE). If you want more details there is a great website which explains about them, but very simply they are controlled, secure, digital platforms for storing, linking and analysing health and care data from the NHS England and associated bodies.
There are 12 across the country, and they are a vital resource for research. Data stays inside the environment; approved users access and analyse the data without downloading or moving it and there are strict controls over who can access, what they can access, what they can do with the data.
Where London’s SDE differs is that we are the only SDE in the country which supports not just academic research, but, critically, secure access for population health analysis, planning and decision making, and even further than that – to direct clinical care. All together, in one trusted environment.
In a city as diverse as London, this really matters.
For too long, too many communities have been left out of research, unable to feel the benefits. The system has not worked well enough for them, and we have a responsibility to fix it.
Through our work to develop the SDE we have a clear mission: to improve outcomes for all communities in London, including those that are under-represented, who often experience the starkest health inequalities.
Studies show that although under-represented communities – including people from global majority, of lower socio-economic status, with disabilities, mental health, and LGBTQ+ groups – make up nearly 45 percent of London’s population, they only account for closer to 10 to 15 percent of participants in many UK clinical trials.
In some groups, for example those who are Black African and Caribbean, this is (very sadly) much lower – more like 1 to 2%.
These are the people research could help the most, yet they are often not represented in the evidence base.
When we look at conditions like heart disease, the link between inequality and poor health outcomes is impossible to ignore.
In London, people in the most deprived communities, many from global majority backgrounds, are more likely to develop cardiovascular disease earlier, to be treated later, and to live shorter, less healthy lives.
Cardiovascular disease alone drives a 10-year gap in life expectancy between the richest and poorest Londoners.
10 years. We need to act.
One of the new Driver Projects we’re announcing next week is focused on tackling this challenge head-on. By using the London SDE to better understand people’s risk, detect disease earlier, and ensure fairer access to specialist care, it will show how data can help close the gap and improve heart health for every community across our city.
As chair of the OneLondon Data Board, I feel a personal responsibility to make this happen. We need to keep at the front of our minds the Londoners who could have benefited from earlier diagnosis if their community had been better represented in the evidence.
We need to listen to Londoners who want to contribute to research yet feel the system has never been built with them in mind. We owe them better. The London SDE, which will be fully live from 1 April 2026, with linked data for 10 million people, gives us the tools to start to deliver improvements for them all.
We already have strong partnerships across the NHS, academia, industry, and citizen groups, and the SDE gives us a safe, secure foundation to deepen that collaboration. This will be a powerful platform in supporting us to make sure evidence, evaluation and research reflects the full breadth of our city.
If our data does not represent everyone, our discoveries will not work for everyone. Closing that gap sits at the heart of why I am committed to this work, and why our board remains focused on it.
Our vision is simple. Just as a single travelcard lets people move easily across London, we want patients, clinicians, and researchers to navigate the health system with the same simplicity. A system that works for them as a public asset and one that helps us do more for Londoners.
Londoners expect us to do this safely, responsibly, and with everyone in mind. Next week, we take another step toward a future where every community can benefit from the discoveries their data helps create.