CLC Quality Control & Process Improvement 3

Question 1

A laboratory implements a new analyzer and finds the coefficient of variation (CV) for a high-concentration QC material is 2.5% but 8.1% for a low-concentration QC material. This pattern MOST likely indicates:

Accepted Answer

Constant random error

Answer

High CV at low concentrations with acceptable CV at high concentrations is characteristic of constant (absolute) imprecision, which has proportionally more impact near the detection limit.

Question 2

Which document type in a laboratory quality management system describes the step-by-step instructions for performing a specific analytical procedure?

Accepted Answer

Standard operating procedure (SOP)

Answer

Standard operating procedures (SOPs) provide detailed, step-by-step instructions for performing specific laboratory tasks or analytical procedures.

Question 3

A Pareto analysis of laboratory errors reveals that specimen labeling errors, centrifugation problems, and wrong tube type together account for 78% of all pre-analytical errors. This finding supports which principle?

Accepted Answer

The 80/20 rule

Answer

The Pareto principle (80/20 rule) states that approximately 80% of effects come from 20% of causes, guiding prioritization of improvement efforts.

Question 4

During proficiency testing (PT), a laboratory's result for a serum sodium sample is flagged as unacceptable. The FIRST action the laboratory director should take is:

Accepted Answer

Investigate the cause through root cause analysis

Answer

Root cause analysis must be performed first to identify why the PT failure occurred before corrective action can be appropriately targeted.

Question 5

In a laboratory QC program, what is the PRIMARY purpose of using two levels of controls (normal and abnormal)?

Accepted Answer

To detect errors across the analytical measurement range

Answer

Running QC at both normal and abnormal concentrations verifies method performance across clinically relevant portions of the analytical measurement range.

(CLC) Certified Laboratory Consultant Practice Test

(CLC) Certified Laboratory Consultant Practice Test

CLC Quality Control & Process Improvement 3