Lecture 56 - Epidemiology 8 (Testing 1)

Question 1

what is the “gold standard” of diagnosis

Answer 1

define the disease as to judge findings from individual clinical signs and/or tests

Question 2

sensitivity of a test

Answer 2

how good is a test for identifying animals WITH disease

probability of positive test among animals with disease (TP/D+)

Question 3

specificity of a test

Answer 3

how good is a test for identifying animals WITHOUT disease

probability of negative test among animals without disease (TN/D-)

Question 4

when would a more specific test be preferred

Answer 4

1. disease is not life-threatening if left untreated
2. costs of treatment are high
3. invasive procedures would be required

Question 5

when would a more sensitive test be preferred

Answer 5

1. disease is life-threatening if left untreated
2. survival rate is improved with immediate treatment

Question 6

accuracy

Answer 6

(TP + TN) / (TP + FP + TN + FN)

Question 7

positive predictive value

Answer 7

the probability that an animal has the disease given that a positive test has been obtained

TP / T+

Question 8

negative predictive value

Answer 8

the probability that an animal does not have the disease given that a negative test has been obtained

TN / T-