Intro To Clinical Med Flashcards
Why is clinical/medical laboratory important?
- provides objective data for evidence based medicine
What is the difference between clinical pathology vs anatomic pathology?
- clinical pathology tests specimens such as blood and urine for hematology, chemistry, immunology etc.
- anatomic pathology tests body tissues for biopsy, autopsy and histology
What is POCT?
- Point of care testing is test that can be done at bedside such as UA, FSBG, pregnancy test and urine dip stick
What testings are waived under CLIA?
- POCT as they are considered low risk for incorrect results and they are pretty easy to perform
What is the difference between internal vs external quality control?
- Internal quality control is testing the kit/product on day to day basis for daily precision and accuracy. Ex. doing control test on pregnancy kit to make sure it works.
- External quality control is for long term accuracy, so making sure competencies are done and training is done correctly. This ensure protocols are being followed correctly for a long term proficiency of the lab.
What is reference range?
- 95% of common range of values from people who are healthy, for comparison/reference to what a healthy range should be.
What is a desirable range?
- range of values that are recommended/accepted for people with certain illness that would change their normal/reference range.
What is a therapeutic range?
- range of values that are recommended/accepted for people on certain drugs that effect/change their normal/reference range
What is a critical value?
- Value that is critically out of range for the patient. Ex. lactate of 6, sodium of 125 or 160 instead of 140
What is positive predictive value (PPV)?
- given that the test is positive, what is the chance that they have the disease
- P(D+/T+)
What is negative predictive value (NPV)?
- likelihood of the negative test result to identify someone without the disease
- given that the test is negative, what is the chance that they dont have the disease
- P(D-/T-)
What is sensitivity of the test (Sn)?
- probability testing positive given that you have the disease
- given that you have the disease, what is the chance that your test is positive
- P(T+/D+)
What is specificity of the test (Sp)?
- Probability of testing negative given that you don’t have the disease
- given that you do not have the disease, what is the chance that your test is negative
- P(T-/D-)
How to increase sensitivity of the test?
- increase threshold to get all positives even false positives, meaning even if the patient does not have the disease there is a chance they will test positive. But if they are negative, there is more chance that they don’t have the disease, so it is a good rule out test.
- 95% sensitivity = 95% of people with disease detected.
How to increase specificity of the test?
- decrease threshold to get all negatives even false negatives, meaning even if the patient does have the disease, there is chance they will test negative. But if you do get positive result, there is more chance that you do have the disease, so it is a good rule in test.
What is the equation of PPV/precision?
PPV = TP / (FP+TP)
What is the equation of NPV?
NPV = TN/(TN+FN)
What is the equation for accuracy?
Ac = (TN+TP) / (TN+TP+FN+FP)
What is the equation for sensitivity?
Sn = TP/(TP+FN)
What is the equation for specificity?
Sp = TN/(TN+FP)
What are the indications needed to order a lab test?
- Screening
- Diagnosis
- monitor disease
- monitor therapy/medicine management
- testing related to specific event
What must be included on the specimen label?
- pt name
- pt DOB
- collection date and time
- Name/initial of person collecting the specimen
What are the 3 veins used for venipuncture/blood draws?
- Median cubital vein
- Basilic vein
- Cephalic vein
What happens to the needle size as the gauge increases?
- the needle size decreases
