2.6 Screenings in Medicine Flashcards
What are 2 questions you should ask your physician when a medical screening test is recommended?
- How accurate is the test. 2. How confident will you be in your prediction of whether i do or dont have disease
What are the 4 screening outcomes?
True positive. True Negative. False Positive. False negative.
What does a True positive mean?
Test reports positive and the presence of disease does exist.
What does a True negative mean?
Test reports negative and the presence of disease doesnt exist.
What does a False positive mean?
Test screams positive but pts doesnt actually have disease.
What does a False Negative mean?
Test reports no disease but pt does have disease
What two terms describe the accuracy of a Test result?
Sensitivity and specificity.
What does sensitivity mean?
How well a test can detect presence of disease when in fact disease is present.
How would you calc sensitivity?
True positives / ( All diseased) x 100%
What is specificity?
How well a test can detect absence of disease when the disease is absent.
How would you calc specificity?
True negatives / (all not diseased) x 100%
What two terms describe how confident the doctor will be about predicting if the pt will have disease or not?
Positive Predictive Value and Negative Predictive Value.
What does the Positive Predictive Value (PPV) show?
How accurately a positive test predicts the presence of disease.
How do you calc PPV?
True positives / (All positive tests) x 100%
What does the Negative Predictive Value (NPV) show?
How accurately a negative test predicts the absence of disease.