Screenings in Medicine

Question 1

What two questions should you, as a patient, ask your physician before consenting to a test?

Answer 1

How accurate is the test?

How confident are you as a physician in the determining my disease status after results are in?

Question 2

True Positive in Box

Answer 2

A

Question 3

True Negative in Box

Answer 3

D

Question 4

False Positive in Box

Answer 4

B

Question 5

False Negative in Box

Answer 5

C

Question 6

The the word accurate in the patient’s first question is determined by…

Answer 6

Sensitivity (Should ideally be 100%)
Specificity

Compared to gold standard

Question 7

What is Sensitivity?

Answer 7

The degree of accuracy that a test can correctly detect presence of disease in those that are known to have disease.

Question 8

What is specificity?

Answer 8

The degree of accuracy that a test can correctly detect absence of disease in those that are healthy.

Question 9

A high sensitivity test has a low ____ and a high specificity test has a low ___.

Answer 9

false negative rate

False positive rate

Question 10

Calculating Sensitivity

Answer 10

True Positive / (true positive plus false negative)

Denominator all disease

Question 11

Calculating Specificity

Answer 11

True negative / (true negative and false positive)

Question 12

The confidence in a physician’s interpretations is determined by

Answer 12

Positive Predictive Value

Negative Predictive Value

Question 13

Positive predictive value determines

Answer 13

how accurately the positive test predicts presence of disease

Question 14

Negative predictive value determines

Answer 14

how accurately the negative test predicts the absence of disease

Question 15

Calculating positive predictive value

Answer 15

True Positive / ( true positive and false positive) or all positives

Question 16

Calculating negative predictive value

Answer 16

True negative / ( true negative and false negative) or all negatives

Question 17

The more frequent a disease is in the community, _____

Answer 17

the easier it will be to find that disease in that community

Question 18

As prevalence changes, ____ doesn’t change but ___ changes

Answer 18

Accuracy of a test (sensitivity)

Predictive Value

Question 19

Diagnostic Accuracy is ___

Answer 19

Proportion of total screenings that a patient is correctly identified as either having disease or NOT having disease

TN + TP / (Total Pop)

If diagnostic accuracy is 100%, no presence of FN or FP

Question 20

Likelihood Ratio Positive

Answer 20

Positive ratio of Disease / Ratio of Non-diseased positive

TP/ Total Pop Dx // FP/ Total Pop healthy

Question 21

Likelihood Ratio Negative

Answer 21

FN/ Total Pop Dx // TN/ Total Pop healthy