There are many bits of your health data. Some captured and digitized, some locked in ‘other companies (hospitals) databases. In order to get the best of the medical treatment. the doctor should get a complete picture of your health, even if possible historic health-related information.
Imagine, if ALL the health-related data is available in one place, and that is owned by yourself, you would be in a much better position to make wise health decisions, yourself, or your consultant, physician, can treat you much better.