SM Quality Assurance & Compliance 4

Question 1

Which Westgard rule is MOST effective at detecting random error in QC data?

Accepted Answer

R-4s rule

Answer

The R-4s rule (range between two consecutive QC values exceeds 4 standard deviations) is specifically designed to detect random error.

Question 2

A laboratory receives notification of a critical value for a positive blood culture. The technologist calls the ordering physician but is unable to reach them. What is the BEST next action?

Accepted Answer

Report to the nursing staff or another responsible licensed caregiver and document

Answer

Critical value notification must reach a responsible licensed caregiver; when the ordering physician is unavailable, the result should be reported to the nurse or covering physician and documented.

Question 3

Which CLSI document provides guidance on verification of antimicrobial disk diffusion procedures for clinical laboratories?

Accepted Answer

M02

Answer

CLSI M02 covers performance standards for antimicrobial disk diffusion susceptibility tests, including procedural verification guidance.

Question 4

During an internal audit, it is discovered that technologists have been recording QC results after running patient samples. This violates which QC principle?

Accepted Answer

QC before patient testing

Answer

QC must be performed and accepted before patient specimens are analyzed to ensure the analytical system is functioning correctly at the time of testing.

Question 5

A Gram stain reagent is found to decolorize gram-positive organisms, making them appear gram-negative. The MOST likely cause is:

Accepted Answer

Over-decolorization with acetone-alcohol

Answer

Excessive decolorization with acetone-alcohol removes the crystal violet-iodine complex from gram-positive organisms, causing them to appear gram-negative (false negatives).

(SM) Specialist in Microbiology Practice Test

(SM) Specialist in Microbiology Practice Test

SM Quality Assurance & Compliance 4