Coagulation QC is performed with how many levels and how often?

• A. 3 levels every 24 hours
• B. 2 levels every 24 hours
• C. 2 levels every 8 hours
• D. 4 levels every 24 hours

Answer: (A)

Coagulation QC uses multiple control levels to verify that clot-based tests are accurate and precise across the range you routinely measure. Using three levels—low, normal, and high—lets you check performance not only at the typical result but also at extremes where bias or imprecision can become evident. Running these three levels once every 24 hours provides a practical, consistent daily monitor of the instrument, reagents, and method, helping catch shifts or drift before patient results are affected.

Choosing only two levels would risk missing issues that occur at concentrations outside the normal control point, while four levels adds more materials without necessarily improving detection of common drift, and checking more frequently than daily can be unnecessarily burdensome for routine testing.