NHA Phlebotomy Certification Practice Exam

Which factor can affect the accuracy of test results in phlebotomy?

1. Patient's age

2. Time of sample collection

3. Type of tube used

4. All of the above

The correct answer is: All of the above

In phlebotomy, the accuracy of test results can be influenced by several factors, and all the choices listed contribute significantly to this. The patient's age can affect how certain conditions present themselves in the body, which can, in turn, impact laboratory results. For instance, normal values for certain blood components can vary between children, adults, and the elderly due to physiological differences. The time of sample collection is crucial, as various analytes can fluctuate throughout the day. Hormone levels, for example, may have diurnal variations, meaning they differ at different times of day. Thus, collecting a sample at the right time is essential for obtaining accurate results that reflect the patient's true status. The type of tube used for collecting the blood sample is equally important. Different tubes contain various additives that preserve the specimen or prevent clotting. Using an inappropriate tube can alter the test results, as these additives can interact with the blood sample negatively or interfere with specific tests. Since all these factors—patient age, time of sample collection, and type of tube used—can independently influence the reliability of test results, it is accurate to say that all of the choices contribute to what can affect the accuracy of results in phlebotomy.