Probability in decision making

Yes or no is what type of data

nominal data

Mild, moderate, or severe is what type of data

ordinal data

A scale with known intervals or cut off values is what type of data

continuous data

What will you need to do as a practicing veterinarian as it pertains to probability

• interpret diagnostics

• calculate level of certainty

• select most appropriate test

What are two levels of probability

• population

• individual

the likelihood that an animal has the disease prior to a diagnostic test is known as a ______

pre test probability

What influences pre test probability

• prevalence in population

• risk factors

• clinical exam findings

True prevalence is ______ divided by ______

• total diseased

• total population

apparent prevalence is ______ divided by _______

• total with a positive test

• total population

The probability that an animal known to have the disease gets a positive result is called _____

sensitivity

The probability that an animal known not to have the disease gets a negative test is called _______

specificity

If you have 100% sensitivity you should get no ________

false negatives

if you have 100% specificity you should get no ________

false positives

the probability that the positive test result is correct is known as _______

positive predictive value

the probability that the negative test result is correct is known as _________

negative predictive value