The screened patients are not coded but are identified using their Civil Registration Number (CPR) for several reasons. The study is open-label, which removes the need for blinding of patients as well as investigator. Blood samples are booked electronically and printed labels with CPR number are put on the test tubes for both immediate analysis and storage. This guarantees a more fail-safe method for handling of various analyses, since this procedure is similar to the routine procedure. We find this to be the safest system as the method, by which labels with CPR number follow the patient has been thoroughly tested.