When we defined the normal range for test X for example in the VISTA system we defined it as (1-5 g/L). However, what if we had to change the methodology for that test and we need to change the normal range but we need to keep the old normal range fixed for the old lab results and the new normal range be implemented for the test starting from next day?

Please we don’t want to define a new test (for example test X new methodology) because this will confuse the medical staff after sometime because they will not know which test they have to order.

Looking forward for your kind response.

Thank you