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Epidemiology Exam Week 2 > Screenings in Medicine > Flashcards

Flashcards in Screenings in Medicine Deck (21)
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1

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

How accurate is the test?

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

2

True Positive in Box

A

3

True Negative in Box

D

4

False Positive in Box

B

5

False Negative in Box

C

6

The the word accurate in the patient's first question is determined by...

Sensitivity (Should ideally be 100%)
Specificity

Compared to gold standard

7

What is Sensitivity?

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

8

What is specificity?

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

9

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

false negative rate

False positive rate

10

Calculating Sensitivity

True Positive / (true positive plus false negative)

Denominator all disease

11

Calculating Specificity

True negative / (true negative and false positive)

12

The confidence in a physician's interpretations is determined by

Positive Predictive Value

Negative Predictive Value

13

Positive predictive value determines

how accurately the positive test predicts presence of disease

14

Negative predictive value determines

how accurately the negative test predicts the absence of disease

15

Calculating positive predictive value

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

16

Calculating negative predictive value

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

17

The more frequent a disease is in the community, _____

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

18

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

Accuracy of a test (sensitivity)

Predictive Value

19

Diagnostic Accuracy is ___

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

20

Likelihood Ratio Positive

Positive ratio of Disease / Ratio of Non-diseased positive

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

21

Likelihood Ratio Negative

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