Right now, medical records are owned by insurance companies, hospitals and clinics. This means that doctors must deal with incomplete views of their patients.
There are two ways to solve this problem: One could have the medical records controlled (owned) by one monolythic group like the Federal Government or perhaps a politically favored company like GE. This is the direction the Obama Administration hopes to take the nation.
Once all of the records are controlled by one group, then it should be possible to create a complete medical history for each person simply by joining all of the information from these desparate systems. (Assuming the primary key is correct.) The system should be able to protect privacy if the people who design the exchange are all top notch and super honest.
The other way to create complete records for the patient is to have the patient own their own medical records. If people owned their own records, then they would end up accumulating a complete medical record for themselves.
In the Medical Savings and Loan the patient owns the medical records. The system has Health Care Advocates who store the records. They then will help the patient interpret the data for themselves and will present the data to doctors as needed.
In a world where people owned their own medical records, but contracted the storage of records to a safe-keeper, a patient centric industry would evolve that would compete on its ability to present quality information to doctors while providing security for the customer.