Quality Control

Question 1

Results should be within _____ SD of mean.

Answer 1

Two

Question 2

How is the control target range created?

Answer 2

By measuring the control a number of times, and the mean +/- two SD establishes the mean for the laboratory/method/conditions

Question 3

Outline the procedure involved when using an external QA service, such as NEQAS

Answer 3

Samples are sent to participating laboratories

Samples are tested as if they were patient samples, and results are returned to the scheme HQ

Results are analysed and compared with other laboratories using same method and/or same instrumentation

Laboratories are informed of performance within their group and overall, with access of results online

Essential for laboratory accreditation to be member of an EQA scheme for every test service provided

Question 4

What is the function of a Delta check?

Answer 4

A Delta check examines result obtained for an analyte with previous result. Changes are compared to limits that are determined by each lab, dependent on method in us, and Delta checks account for analytical and biological variation

Question 5

________ ______ look at the result, to ensure that it is physiologically possible.

Answer 5

Range checks

Question 6

What are the three facets of QC in the clinical chemistry laboratory?

Answer 6

Internal QC
External QA
Clinical validation

Question 7

List two important tools of internal QC.

Answer 7

Levey-Jennings charts and Westgard rules