Final answer:
External liquid controls for a CLIA-waived glucose point-of-care test should be performed when a new lot number or kit is opened to ensure the test is providing accurate results.
Step-by-step explanation:
When a phlebotomy technician performs external liquid controls for quality control on a CLIA-waived glucose point-of-care test, they should conduct these controls when a new lot number or kit is opened. It is not necessary to perform this quality control with every patient, every week, or when a different technician performs the test unless specifically required by lab policy or standard operating procedures. External liquid controls are critical to ensure the test is working correctly and providing accurate results, particularly when starting a new test kit or lot number, as variations can occur between batches.