1. What should I do if I forget to save one urine sample during the collection?
If you do not have a complete collection, the results will not be valid. You should either call your doctor or the laboratory where you obtained your container to ask if you should discontinue the test and begin again another day.
2. Is this test extremely accurate?
There are other, more involved tests that have higher accuracy. However, these are more complex for the patient and doctor and involve injecting the patient with a tracer and are more expensive. For most medical purposes, the accuracy of creatinine clearance is sufficient. Very similar information to that produced by the more complex tests can be obtained using estimated GFR, which does not require a urine collection. Creatinine clearance measurement is new rarely necessary in clinical practice.
