MLS Quality & Safety 2

Question 1

A laboratory receives a proficiency testing (PT) sample and the result is flagged as 'unacceptable.' What is the most appropriate immediate action?

Accepted Answer

Investigate the root cause and document corrective action

Answer

Unacceptable PT results require root cause investigation and documented corrective action per CLIA and accreditation standards.

Question 2

Which statistical term describes the degree to which repeated measurements of the same sample yield the same result?

Accepted Answer

Precision

Answer

Precision (reproducibility) refers to the closeness of repeated measurements to each other, independent of the true value.

Question 3

A CBC analyzer's WBC results are consistently 15% higher than expected based on the reference method. This error is best described as:

Accepted Answer

Proportional systematic error

Answer

Proportional systematic error increases with analyte concentration, producing a consistent percentage deviation from the true value.

Question 4

When performing a Levey-Jennings chart review, which Westgard rule is violated when one control value exceeds the mean by more than 3 standard deviations?

Accepted Answer

1-3s rejection rule

Answer

The 1-3s rule is a rejection rule triggered when a single control value falls outside ±3 SD, indicating probable random or systematic error.

Question 5

A chemical spill of sulfuric acid occurs in the chemistry lab. The FIRST action the MLS should take is:

Accepted Answer

Don appropriate PPE before approaching the spill

Answer

Personal protective equipment must be donned before approaching any chemical spill to protect the MLS from exposure.

(MLS) Medical Laboratory Scientist Practice Test

(MLS) Medical Laboratory Scientist Practice Test

MLS Quality & Safety 2