Intro to lab medicine Flashcards
Accuracy
How closely the test results correspond to the gold standard. How often is test right
Precision
How reproducible are the results
Specificity
% of people without the disease and a negative test result. RULE IN (SPIN)
Sensitivity
% of people who have the disease and have a positive test result. RULE OUT (SNOUT)
Predictive value
Estimation of the probability of the presence or absence of disease
False positive
Postive test result in a pt who does NOT have the disease
False negative
Negative test result in a pt who DOES have the disease
Prevalence
of cases of disease in a population
Likelihood ratio
How likely is it that this test is going to help. LR+ >1 indicates test is associated with disease.
LR-
Pretest probability
Probability of a pt having the disease before test results
Posttest probability
Proportion of pts testing positive who truly have the disease
Positive predictive value
% of people with a positive test who DO HAVE the disease
Negative predictive value
% of people with a negative test who DO NOT HAVE the disease
What is the equation for PPV
TP/TP + FP X 100
What is the equation for the NPV
TN/TN + FN X 100
Equation for sensitivity
TP/ TP + FN
Equation for specificity
TN/ TN + FP
What is a Critical PANIC value
It is a lab finding that is emergent and needs to be reported immediately to the clinician
CLIA
Clinical laboratory improvement amendments
CLIA waived test
Test that poses no or low risk for erroneous results. They are tests that are also approved for home use
CLIA provider performed microscopy test
- exam must be performed by a physician or mid-level
- Moderate complexity
- Instrument must be a microscope
- Limited specimen handling is required
Dipstick urinalysis
Thin strip placed in urine, results in a color change due to pH levels (also measures, proteins, ketones, bill, blood)
Fecal occult blood testing
Smear stool on a Guiac card, tests for blood in the stool
Urine pregnancy test
Pee on a dipstick, measures the presence of hCG
Erythrocyte sedimentation test
ESR, used to detect inflammation associate with infections, cancer, autoimmune disorders
Spun hematocrit
Measurement of RBC count, usually part of the CBC. Detects anemia
Wet mount
Microscopic exam of vaginal discharge for bacterial vaginosis, candida, increased WBC
Potassium hydroxide mount (KOH)
Microscopic exam of skin, hair, nails, vaginal discharge, confirms if there is a presence of a species (often fungal)
Pinworm prep
Tape on anus, looking for helminths
Capillary blood glucose
Monitors blood glucose (pin prick on finger)
Ovulation test
Measure of LH (luteinizing hormone). Surges during ovulation and used to monitor menstrual irregularities, infertility.
