Data is a valuable resource in the NHS. Careful study of the statistics of disease and mortality can lead to understanding that saves lives - like the understanding that smoking cigarettes can cause lung cancer. Data relating to hospital episodes has been collected and studied for many years. The new "Care.Data" program is intended to allow data held at GP surgeries to be studied in a similar way. Data is to be anonymised and linked to hospital and other medical data and permission is given for this on a project by project basis.