Introductory Concepts

Question 1

What are the analytical properties of assays?

Answer 1

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

Question 2

What is analytical precision (systematic error)?

Answer 2

Precise, but not accurate

Systematic error is an error that is always occurring similarly, but doesn’t render the test unuseful

Question 3

What is analytical imprecision?

Answer 3

The presence of random error

Question 4

What is analytical precision and accuracy?

Answer 4

An assay that is accurate and precise

It doesn’t have systemic or random errors

Question 5

What is analytical specificity?

Answer 5

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

Question 6

What is the detection limit?

Answer 6

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

Question 7

How are reference intervals established?

Answer 7

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

Question 8

What is a reference limit?

Answer 8

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

Question 9

What is the decision threshold?

Answer 9

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

Question 10

What determines the quality of lab results?

Answer 10

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

Question 11

What is quality assurance?

Answer 11

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

Question 12

What contributes to preanalytical errors?

Answer 12

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

Question 13

What contributes to analytical errors?

Answer 13

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

Question 14

What contributes to postanalytical errors?

Answer 14

Transcriptional errors

Graphic quality of report

Question 15

How do you choose a lab?

Answer 15

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

Question 16

What are advantages to an in-house lab?

Answer 16

24 hours access
Short turn around time
Fresh sample

Question 17

What are disadvantages to an in-house lab?

Answer 17

Cost
Maintaining inventory
Training of personnel
Quality assurance program
Reference intervals?

Question 18

What are advantages to a veterinary reference lab?

Answer 18

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

Question 19

What are disadvantages to a veterinary reference lab?

Answer 19

Sample may deteriorate

Turn around time is variable

Question 20

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

Answer 20

Turn around time is usually short

Question 21

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

Answer 21

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