Depending on the test system, the laboratory may choose either a comparison or reference method to verify test accuracy.
With the comparison method, the laboratory assesses theaccuracy using split samples. For example, the laboratory obtains 20 patient samples with test results covering the reportable range of the test system. The samples are split and tested on the new test system and by a comparative method either in house or by sending them to another facility with the same test system. The laboratory compares the results from the two methods or instruments to determine if significant differences exist. Accuracy is considered met if the laboratory's percent bias is not greater than the manufacturer's claim.
With the reference method, the laboratory assessesaccuracy using reference materials with known values that cover the entire reportable range of the test system. Using the assayed reference material, for example, the laboratory compares the results obtained from the new test method to the expected reference value. Accuracy is considered met if the results are within the assayed methods.