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Flashcards in Introductory Concepts Deck (21):

What are the analytical properties of assays?

Analytical precision (systematic error)
Analytical imprecision (random error)
Analytical precision and accuracy
Analytical specificity
Detection limit


What is analytical precision (systematic error)?

Precise, but not accurate
Systematic error is an error that is always occurring similarly, but doesn't render the test unuseful


What is analytical imprecision?

The presence of random error


What is analytical precision and accuracy?

An assay that is accurate and precise
It doesn't have systemic or random errors


What is analytical specificity?

An assay that is specific towards one thing. If something show up that you were not looking for, then the test is not as specific


What is the detection limit?

The lower and upper detection limits of a test that accommodates all the clinical means


How are reference intervals established?

60-120 animals of each species
Qualifying criteria:
Young adults
Clinically healthy
Represent the animal population of the region


What is a reference limit?

The range that is considered normal which is 95% of the population (2.5% is removed from the lower and upper levels)
A value of a test that is above or below the reference limit may indicate pathological state


What is the decision threshold?

A value of a test that is used to classify as positive or negative for a disease, or more importantly used to decide changes in treatments


What determines the quality of lab results?

Quality of the sample
Quality of the analysis
Quality of the lab records


What is quality assurance?

Preanalytical errors (quality of sample)
Analytical errors (quality of analysis)
Postanalytical errors (quality of lab records)


What contributes to preanalytical errors?

Sample collection (preparation of patient-fasting, collection technique, collection container, anticoaglant, sample volume)
Sample handling (proper labeling, appropriate temperature, prompt processing)


What contributes to analytical errors?

Method appropriate for species
Quality of instruments and equipment
Quality of reagents
Quality of lab techniques
Quality control program (assessment of variation on results)


What contributes to postanalytical errors?

Transcriptional errors
Graphic quality of report


How do you choose a lab?

How will the results affect the care of the patient?
Will the lab provide consistent quality?
Importance of a short turnaround time


What are advantages to an in-house lab?

24 hours access
Short turn around time
Fresh sample


What are disadvantages to an in-house lab?

Maintaining inventory
Training of personnel
Quality assurance program
Reference intervals?


What are advantages to a veterinary reference lab?

Personnel trained
Diagnostic support may be available
Appropriate reference intervals
More tests available
Cost per sample is clear


What are disadvantages to a veterinary reference lab?

Sample may deteriorate
Turn around time is variable


What is the advantage to a lab in a local human hospital?

Turn around time is usually short


What are disadvantages to a lab in a local human hospital?

Reference intervals may not be established by the lab
Assay methods may not be appropriate
Personnel may not know species variations