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
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
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?
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
What are disadvantages to an in-house lab?
Training of personnel
Quality assurance program
What are advantages to a veterinary reference lab?
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