Clinical Decision Making Flashcards
Steps 1-3 of the Diagnostic Process
- Identify problem through history, physical, and test results
- Frame differential diagnosis
- Organize and limit differential and include “Must Not Miss Possibilities”
Steps 4-6 of the Diagnostic Process
- Utilize key features in the case
- Rank differential diagnosis
- Test hypothesis to make diagnosis
What 2 thresholds do we utilize? What determines whether we test or treat?
- Test threshold
- Treatment threshold
Pre-test probability
Sensitivity
Percentage of patients with the disease that have a positive result
What does a test with high sensitivity that is negative imply?
Post-test probability of the disease is low
Overall, sensitivity helps what?
Rule out the disease, as long as pretest probability of disease is not super high
Specificity
Percentage of people without the disease who have a true negative result
A test with a high specificity that is positive is likely what?
True positive unless pretest probability of disease is really low (positive pregnancy test in male)
Pre-Test Probability
Probability of disease or condition being present in population you are examining
When is performing tests on a patient most helpful?
When pre-test probability of the disease is intermediate
Post-Test Probability
Probability of disease being present after using test results
Positive Predicted Value
Probability that patients with positive test actually have the condition
PPV is dependent on what?
Prevalence of the condition in the population being tested
Likelihood ratio
Ratio of the likelihood that a given test result would occur in patients with the condition compared to a patient without the condition
The likelihood ratio is NOT dependent on what?
Prevalence of the condition in the population
