The One London scheme aims to pioneer linking and sharing records across the capital.
They are inviting Londoners to have their say on how their data is used.
How do you want your health and care information to be used? Who do you think it should be accessed by and for what purposes? Do you only want your data to be used by doctors and nurses to support your individual care? Or if your data is kept anonymous, would you be happy for it to be used to plan better services or to support research into better treatments?
You can share your comments on the One London website.