In laboratory testing, the greatest percentage of errors occurs during which phase?

In laboratory testing, the greatest percentage of errors occurs during which phase?

• A. Preanalytical
• B. Analytical
• C. Postanalytical
• D. Proficiency

Answer: (A)

The phase before the sample is actually analyzed—the preanalytical stage—produces the most errors. This stage includes everything up to the moment the specimen is placed on the analyzer: how the patient is prepared, how the blood or other sample is collected, labeled, transported, and processed. A large variety of problems can creep in here, and they often directly affect the integrity of the sample before any measurement happens. Examples include misidentifying the patient, using the wrong collection tube or additives, improper venipuncture causing hemolysis or contamination, insufficient sample volume, delays in transport, temperature excursions, and inadequate mixing or clotting in the sample. Once the sample quality is compromised, the analytical results can be unreliable, and those issues are not easily corrected by the testing process itself. In contrast, the analytical phase is focused on measurement and is tightly controlled with calibration and quality checks, and the postanalytical phase deals with reporting and interpretation.

The phase before the sample is actually analyzed—the preanalytical stage—produces the most errors. This stage includes everything up to the moment the specimen is placed on the analyzer: how the patient is prepared, how the blood or other sample is collected, labeled, transported, and processed. A large variety of problems can creep in here, and they often directly affect the integrity of the sample before any measurement happens. Examples include misidentifying the patient, using the wrong collection tube or additives, improper venipuncture causing hemolysis or contamination, insufficient sample volume, delays in transport, temperature excursions, and inadequate mixing or clotting in the sample. Once the sample quality is compromised, the analytical results can be unreliable, and those issues are not easily corrected by the testing process itself. In contrast, the analytical phase is focused on measurement and is tightly controlled with calibration and quality checks, and the postanalytical phase deals with reporting and interpretation.