Lab Medicine

Question 1

accuracy

Answer 1

how closely the test results correspond to the true value or “gold standard”

Question 2

precision

Answer 2

how reproducible the results are with repeat testing (can be precise without being accurate)

Question 3

specificity

Answer 3

SPIN - specificity RULE IN–less false negative results; you’re really sure a + result is actually positive

Question 4

sensitivity

Answer 4

SNOUT - sensitivity RULE OUT–less false negatives; really sure a - result is actually negative

Question 5

predictive value

Answer 5

how true is the predicted result?
+ predictive value=% of persons with a + result who DO HAVE the disease
- predictive value=% of persons with - result who DO NOT have the disease

Question 6

false positive

Answer 6

+ test result without presence of disease

Question 7

false negative

Answer 7

• test result with disease present

Question 8

prevalence

Answer 8

proportion of population who have a condition

Question 9

pretest probability

Answer 9

if you’re part of an at risk population, the probability based on data you have the disease

Question 10

five reasons for ordering lab measurement

Answer 10

1. discover disease, 2. confirm diagnosis, 3. differentiate between diagnoses, 4. stage, activity or severity of disease, 5. assess/monitor treatment effectiveness

Question 11

sources of error that affect quality of lab tests

Answer 11

patient variables, collection variables, handling variables

Question 12

wet mount

Answer 12

vaginal discharge on slide looked at under microscope

Question 13

KOH mount

Answer 13

same as wet mount bur add KOH (kills bacteria and human cells–clearly see if yeast is present)

Question 14

pinworm prep

Answer 14

piece of tape over the rectum and look under microscope to see eggs

Question 15

CBG capillary blood glucose

Answer 15

glucometer

Question 16

ovulation test

Answer 16

leutinizing hormone in the blood