Flashcards in Epidemiology Deck (11):
What are the parts of PICO?
-intervention (experimental group)
-comparison (control group)
What drags down sensitivity?
Sensitivity + FNR = 100%
Formula and definition of sensitivity
Sensitivity = a / (a+c)
-true positive rate
-what percent of ppl w/ the disease get a positive test result
Formula and definition of specificity
Specificity = d / (b+d)
-true negative rate
-what percent of ppl w/o the disease get a negative result
What is the real value of interest of a test result
Positive predictive value (which = posttest probability)
-value of ppl w/ a positive result who truly have teh disease
Formula and definition of PPV
+PV = a / (a+b)
-proportion of ppl w/ a positive test result who actually have the disease
Formula and definition of NPV
-PV = d / (c+d)
-proportion of ppl w/ a negative test result who truly don't have the disease
What result from what kind of test would rule a diagnosis in ?
-positive result on a specific test (low false positives) rules in a diagnosis
What results from what kind of test would rule out a diagnosis?
-negative result on a sensitivity test (low false negative) rules out a diagnosis
Describe what a likelihood ratio is
LR is one test result for two populations
ex] LR of 11 means that the test results are 11 times more likely in a patient with the disease than in a patient without the disease