Delta checks in laboratory data are used to detect discrepancies between current and prior results in which two error categories?

• A. Analytical and Pre-Analytical
• B. Post-Analytical and Administrative
• C. Analytical and Post-Analytical
• D. Pre-Analytical and Post-Analytical

Answer: (A)

Delta checks compare the current result with the prior value for the same patient to spot unusual changes. When a result deviates significantly from what was previously seen, it often points to issues in how the specimen was handled or prepared (pre-analytical) or in the measurement itself (analytical). For example, a hemolyzed or poorly collected sample can skew results before they’re analyzed, or a calibration issue or instrument drift can produce erroneous measurements. Errors that occur after analysis—such as data entry or reporting mistakes—don’t reflect a true change in the patient’s specimen and are not the primary focus of delta checks. So delta checks are most informative for detecting problems in analytical and pre-analytical phases.