Encyclopedia

Screening cutoff depends on units, method, medications, potassium, and collection protocol.

How you sit or lie down for the sample, and stress during collection, can affect this result. Use the cutoff from the lab that ran your test.

Ask your clinician to specify whole blood, RBC, plasma, or intracellular method. Preanalytic handling is critical.

The test method and how the sample is protected after collection can affect this number.

This ratio is useful only when both measurements were made using a reliable paired method.

RBC, plasma, and cellular assays are not interchangeable.

The method can change the result; ask what clinical question the test is meant to answer and whether a repeat would help.

Urine/plasma method, creatinine correction, collection timing, and assay matter.

Urine/plasma and mass-spec/immunoassay results are not interchangeable.

Ask your clinician to use exact laboratory interval. Clinical utility and treatment targets are not universally standardized.

Assay and indication-specific.

Diet, kidney function, microbiome, timing, and assay affect results.