Final answer:
The medical assistant should perform regular equipment calibration, avoid using expired reagents, not disregard abnormal test results, and document testing procedures to maintain quality control for CLIA-waived testing.
Step-by-step explanation:
To maintain quality control for CLIA-waived testing, the medical assistant should a) calibrate equipment regularly, b) **avoid using expired reagents**, c) **not disregard any abnormal test results**, and d) **document testing procedures**. Calibrating equipment ensures accurate measurements and reliable results. Using expired reagents can lead to inaccurate test results. Disregarding abnormal test results or failing to document testing procedures can compromise patient care and the integrity of the testing process. Using expired reagents, disregarding any abnormal test results, and avoiding documenting testing procedures would all be detrimental to maintaining quality control in a clinical setting and are not recommended practices.