Clinical Prediction Rules and Diagnostic Accuracy

Question 1

Baseline probability of a certain condition before any testing takes place for any given patient

Answer 1

Pre-Test Probability

Question 2

The revised likelihood of the diagnosis based on the outcome of the test

Answer 2

Post-Test Probability

Question 3

Systematically derived and statistically tested combinations of clinical findings that provide meaningful predictions about an outcome of interest
A model that quantifies the contributions of a set of variables to: Diagnosis, prognosis, and likely response to treatment for an individual patient
May include information from the history, physical exam, lab tests, or chief complaints

Answer 3

Clinical Prediction Rules (CPR)

Question 4

Do two criteria measured at the same time correlate?
Sensitivity/specificity
Correlation coefficients

Answer 4

Concurrent Validity

Question 5

Can one criterion predict the magnitude of another?
Correlation coefficients
Regression

Answer 5

Predictive Validity

Question 6

The percentage of times a test obtains a “true” value
Highly influenced by prevalence, so not as useful as other values

Answer 6

Predictive Values

Question 7

The likelihood that a given test result would be expected in a patient WITH the target disorder compared to the likelihood of the same result in a patient without the target disorder

Answer 7

Likelihood Ratios

Question 8

The likelihood a positive test was obtained in someone with the disease is compared to someone without the disease

Answer 8

Positive Likelihood Ratios

Question 9

The likelihood a negative test was obtained in someone with the disease as compared to someone without the disease

Answer 9

Negative Likelihood Ratios