Sensitivity and specificity

What is a false negative?

A person with a disease who tests negative

What is a true positive?

A person with a disease who tests positive

What is a true negative?

A well person who tests negative

What is a false positive?

A well person who tests positive

What is specificity?

If a person does not have a disease, how often will the test be positive? - A highly specific test with a positive result means they most likely do have the disease.

What is sensitivity?

If a person has a disease, how often will the test be positive (true positive) -A highly sensitive test with a negative result means you can be nearly certain you don't have the disease.

A very specific test rules __________ disease with a high degree of confidence.

In

What is NPV?

Negative predictive value?

A sensitive test helps to rule ___________ disease when the test is negative.

Out

How do you measure PPV?

PV+ = true positive/(true positives + false positives)

How do you measure NPV?

PV- = true negative/(true negatives + false negatives)

What is PPV?

Positive predictive values

Sensitive tests are used to _____________ and specific test are used to ______________

Screen, diagnose

Whats the equation for measuring sensitivity?

Sensitivity = true positives/(true positives + false negatives)

Whats the equation for measuring specificity?

Specificity = true negatives/(true negatives + false positives)