Flashcards in Extras for test 1 (intro stuff) Deck (23)
What is the type of laboratory used by the campus clinic?
Commercial laboratory like quest diagnostics.
Name 5 indications for ordering laboratory tests?
1. Confirmation of a clinical impression or establishment of a diagnosis. 2. Rule out a diagnosis. 3. Monitor therapy. 4. Establish a prognosis. 5. Screen for health; preventative medicine.
What is wellness screening?
Testing asymptomatic individuals who are basically healthy.
What type of diseases should be screened for with a wellness screening test?
prevalent, can be detected before clinical findings develop, are treatable, have harmful consequences if left untreated.
What is acuracy and what is percision?
Acuracy- Correctness. How close a test result comes to the true biologic value. Percision- reproducability, how consistant a test result is via multiple testing of the same specimen.
What is sensitivity and specificity?
Sensitivity- True-positive, A highly sensitive test will rule negatives out. Specificity- True-negative, A highly specific test will rule positives in.
In order to detected a disease a tests needs maximum what?
If a test has a very high sensitivity what will specificity be like and what will this mean?
specificity will probably be low, and this results in healthy people being labeled as sick.
A good screening test will have high what?
High sensitivity so it will catch almost all true-positives, but it will include people who are not sick.
What type of test will have a high specificity?
What type of test is used when there is high clinical evidence of a disease?
A highly specific.
What are reference ranges?
Patients test results are reported along with a numerical range of test values that are found in healthy individuals.
How are reference ranges RR established?
Testing on a large number of healthy individuals, then perform a statistical analysis and the results ideally represent a gaussian distribution.
Where will the healthy numbers come from in a RR?
plus or minus 2 standard deviations and this will include 95% of the healthy people so 5% of healthy people will be outliers.
RR are of most value when?
When there are age, gender, and population specific.
What are the test result values given as?
In USA- conventional units. Everywhere besides the USA- SI units or International units which are purely metric.
What are the host factors that add variablity to test results?
age, gender, race.
What is a coefficient of variation (CV)?
a statistical evaluation to determine if the variation of test results from multiple analyses of the same sample is acceptable. The lower the CV the better.
What will make a CV high?
Analytic variation due to methodology. So manual methods can have a CV of 10-15% and automated CV are a few %.
Give some examples of improper patient instructions that can be sources of error in laboratory testings?
Poor patient compliance with fasting vs. non-fasting. Collection of specimen. Exercising prior to test.
What is a profile or panel testing?
Collection of different tests related to a particular organ, organ system, or disease group.
Panels or profile tests allow for what?
Lots of tests at low costs, they help with pattern recognition.