The NHS has a wealth of data which makes conducting studies across large population groups possible. For example Dexamethasone as a treatment for COVID was identified thanks to having access to a medical history and outcome data across the NHS.

Even so there has not historically been a unified data storage solution as information is split between GPs and individual hospital trusts. Previous attempts to have a single system failed due to complexity and cost overruns. The current solution is the federated data platform (FDP): https://www.england.nhs.uk/digitaltechnology/nhs-federated-data-platform/ which attempts to interoperate with multiple primary data sources to help clinicians access patient records as well as help with resource and service planning.

I assume the Palentir system is involved with providing some sort of AI insights into that data store.