13 - evaluation of lab data

Question 1

1. sensitivity = ?
2. specificity = ?

Answer 1

1. ability to find positives
2. ability to find negatives

Question 2

1. positive predictive value = ?
2. negative predictive value = ?

Answer 2

1. percent of patients with positive test results who actually have the disease
2. percent of patients with a negative test who don’t have the disease

Question 3

1. what is the positive diagnostic likelihood ratio?
2. the negative?

Answer 3

1. probability of a + test result in those w/ disease divided by the probability of a + test result in those without the dz
2. probability of a neg test result in those with dz divided by the probability of a negative test result in those without disease