CLIA Testing Procedures & Method Validation 2

Question 1

Which statistical measure is used to assess the systematic error (bias) of a new method compared to a reference method during method validation?

Accepted Answer

Inaccuracy

Answer

Inaccuracy measures systematic error (bias) — the difference between the new method's mean result and the true or reference value.

Question 2

Under CLIA, when must a laboratory re-validate a test method?

Accepted Answer

When there is a significant change in reagents, equipment, or methodology

Answer

CLIA requires re-verification or re-validation whenever a significant change occurs in reagent lots, equipment, or the testing process itself.

Question 3

The Westgard 1₃s rule is violated when:

Accepted Answer

One control value exceeds ±3 SD

Answer

The 1₃s rule is a warning/rejection rule triggered when a single control result falls outside ±3 standard deviations of the mean.

Question 4

What is the primary purpose of performing a linearity study during method validation?

Accepted Answer

To confirm the method produces accurate results across its reportable range

Answer

A linearity study verifies that the method produces results proportional to analyte concentration across the claimed analytical measurement range.

Question 5

A laboratory introduces a new whole blood glucose analyzer. According to CLIA, what is the minimum number of patient samples required for a comparison-of-methods experiment?

Accepted Answer

40

Answer

CLIA guidance (and CLSI EP09) recommends a minimum of 40 patient samples spanning the analytical range for a method comparison study.

(CLIA) Clinical Laboratory Improvement Amendments Certification Practice Test

(CLIA) Clinical Laboratory Improvement Amendments Certification Practice Test

CLIA Testing Procedures & Method Validation 2