If you’re in the U.K., you really should read this post from medConfidential. Here’s an excerpt from it:
As NHS England begins to ramp up again towards the ‘pathfinder’ stage (see our last newsletter) the new narrative seems to be that the data to be extracted from your GP record is only “codes”. Quite aside from the fact that each item will be associated with your NHS number, date of birth, full postcode, gender and ethnicity, these codes are not secret – they are published, and even used in adverts on the sides of trains.
To help you understand the breadth of the information to be extracted under the current version of care.data, we have put together an online tool to let you search and read the diagnoses, treatments and other ‘events’ described by the codes. All the events within the care.data GP dataset will have dates attached and be linked to every other medical diagnosis you have on the dataset, or that can be inferred from your prescriptions.
Read more here.