CLIA Testing Procedures & Method Validation 4

Question 1

A technologist performing a glucose assay obtains QC results of 98 mg/dL and 102 mg/dL for a control with a mean of 100 mg/dL and SD of 3 mg/dL. Which Westgard rule applies?

Accepted Answer

Within acceptable limits — no rule violated

Answer

1₂s warning

Answer

1₃s rejection

Answer

2₂s rejection

Question 2

What is 'carryover' in the context of analytical testing, and why is it evaluated during method validation?

Accepted Answer

The transfer of analyte from a high-concentration sample to a subsequent low-concentration sample, potentially causing falsely elevated results

Answer

The degradation of reagent over time due to temperature changes

Answer

The systematic difference between two analytical methods

Answer

Variation in results caused by different operators

Question 3

Which parameter best describes a method's ability to detect small differences in analyte concentration between two samples?

Accepted Answer

Analytical sensitivity

Answer

Analytical specificity

Answer

Linearity

Answer

Reportable range

Question 4

When validating a laboratory-developed test (LDT) for a high-complexity analyte, which performance characteristic is NOT required by CLIA to be established?

Accepted Answer

Cost per test

Answer

Accuracy

Answer

Precision

Answer

Reportable range

Question 5

A laboratory is validating a new serum creatinine method. Specimens with creatinine >10 mg/dL are routinely diluted 1:5. The laboratory must verify that:

Accepted Answer

The dilution protocol does not alter the matrix significantly and diluted results are accurate

Answer

Dilution is only performed for QC samples, not patient samples

Answer

The lowest reportable value is ≤0.1 mg/dL

Answer

The method's CV is <5% at all dilutions

Question 6

Which statistical test is most appropriate for comparing bias between a new method and a comparative (reference) method in a method comparison study?

Accepted Answer

Paired t-test or Deming regression

Answer

Chi-square test

Answer

ANOVA

Answer

Fisher's exact test

Question 7

According to CLIA, for non-waived tests, how long must a laboratory retain records of quality control results?

Accepted Answer

2 years

Answer

6 months

Answer

1 year

Answer

5 years