Quality Control, Delta Checks and Predictive Values Flashcards
statistical tool used to assure the reliability of patient test results
quality control
acceptable range for quality control is:
Mean +/- 2 SD = 95% *TEST QUESTION!
Which of the following can quality control NOT determine?
A) if the sample is from the correct patient
B) if the analytical run was accurate
A) Quality control CANNOT validate if the sample is from the correct patient. TEST QUESTION!
It can determine if the analytical run: methodology, testing procedure, reagents, entire test system, and instruments are accurate.
T/F If the analytical run is invalid, the we are confident the patients results are valid.
FALSE - if the analytical run results are not within acceptable limits, an ERROR has occurred, and patient results are jeopardized.
Need to fix the error, retest the QC sample and then the patient sample once the error is fixed.
define: Accuracy
closeness of a measurement to the true value
define: Precision
reproducibility of a measurement
define: Reliability
accuracy and precision of a measurement
What is a reference range?
What does a value within the range mean? Outside the range?
range of values the majority of healthy individuals will have
within range: without disease
outside range: likely has disease
A test result that indicates the patient requires immediate medical intervention is called what?
Critical Value
if immediate medical intervention is not received, the patient may die
Qualitative Assays measure: A) Positive/Negative B) Reactive/Non-Recative C) Growth/No Growth D) all of the above
D) All of the above
Control values must yield the expected results before reporting patient results.
Which is not an example of a quality assay example. A) Pregnancy test B) Monospot C) Antigen Typing D) Hemoglobin S E) none - all of the above are examples
E) all of those were examples of quality assay examples
Others include:
Strep throat
Identification Test: catalase, oxidase
Media Checks: growth/no growth
Test Reactivity: Rh-hr/Coombs control cells
What is a Delta Check?
most recent test result for a patient for a particular patient is compared to the most previous test result for that patient
T/F If a test results has changed significantly from the last time a test was done delta check failure has occurred.
True
Common Errors resulting in delta check failure:
the sample may have be compromised (test interference, improper handling, drawn at wrong time, or wrong sample tube)
may be the wrong patient
T/F no method can detect all persons with disease.
T/F no method can detect all persons without disease
TRUE - no test is 100% specific or 100% sensitive
A SCREENING TEST should have high sensitivity/specificity.
SENSITIVITY
will not miss patients with disease
not many false negatives
high negative predictive value
