1 Laboratory Values and Clinical Interpretation Free Online FlashCards

Why is a laboratory result not a diagnosis by itself?

A laboratory result is a measurement or finding, not a diagnosis by itself. Interpret it alongside symptoms, history, examination, other findings, and the reason for testing.

What are the three stages of the laboratory testing process?

The three stages are preanalytical, analytical, and postanalytical.

What happens during the preanalytical stage?

The preanalytical stage includes ordering the right test, identifying the patient, and collecting, labeling, storing, and transporting the correct specimen.

What defines the analytical stage of testing?

In the analytical stage, the laboratory uses a particular method to measure or detect the target. Instruments, reagents, and methods have limits and sources of variation.

What makes the postanalytical stage important for safety?

The postanalytical stage includes checking and reporting results, communicating them, and acting on them. A correct measurement can still be unsafe if it is overlooked or not followed up.

What does a laboratory reference interval describe?

A reference interval describes results observed in a defined reference population under specified conditions. Many intervals cover the central 95% of results in a selected healthy population.

What can and can’t a reference interval establish about health?

Some healthy people fall outside a reference interval, and an in-range result does not rule out disease. Interpret the result in its clinical context.

What is a clinical decision limit?

A clinical decision limit is a threshold linked to a clinical action or risk assessment. It may differ from the reference interval.

What does a positive test result establish?

A positive result means the test detected its target; it does not always establish a diagnosis. False-positive and false-negative results are possible.

What should you verify before comparing laboratory values?

Check what was measured and the units. Do not compare values reported in different units without a verified conversion.

What does a high or low laboratory flag tell you?

A high or low flag marks a comparison with a reference interval or threshold; by itself, it is not a diagnosis or a measure of urgency.

Why can a trend matter even when results remain in range?

A change may matter even when both results remain within the reference interval; for example, a steady rise in a patient-specific marker may warrant evaluation.