[2] Diagnostic Research Design Flashcards Preview

[IDC 212] 1st Lecture Exam > [2] Diagnostic Research Design > Flashcards

Flashcards in [2] Diagnostic Research Design Deck (34)
1

Do you need a diagnosis if pretest probability is 100%?

No, it is not needed

2

Define: Treatment Threshold

Probability above which diagnosis is sufficiently likely to warrant treatment

3

What is the effect of a greater adverse effect of treatment on the Treatment Threshold?

Higher Threshold

4

What is the effect if the next test the patient has to be subjected to is more invasive than the current test to be performed on the Treatment Threshold?

Lowered Threshold

Prevents more people from being subjected to the next more invasive test

5

Define: Test/Diagnostic Threshhold

Probability below which a diagnosis warrants no further consideration

6

What is the effect of a serious missed diagnosis on the Test/Diagnostic Threshold?

Lowered Threshold

Missing diagnosis would be fatal, lowering it would ensure more people to take further tests to confirm

7

What is the effect if the next test to be done is riskier than the current test on the Test/Diagnostic Threshold?

Higher Threshold

This is done to ensure less people take the riskier next test if they don't reach the high enough diagnosis warrant in the first place

8

[Formula]

Likelihood Ratio

Probability of Person w/ the Disease Testing Positive / Probability of a Person w/o the Disease Testing Negative

9

[Interpretation]

LR > 1

Increased disease probability

10

[Interpretation]

LR < 1

Decreased disease probability

11

[T/F]

Diagnostic tests with LRs close to 1 have practical significance

F

Goal is create a significant increase in the post test probability as compared to pre test probability

12

[Interpretation]

LRs > 10 and < 0.1

Large and often conclusive

13

[Interpretation]

LRs 5-10 and 0.1-0.2

Moderate Shifts

14

[Interpretation]

LRs 1-2 and 0.5-1

Small and Rarely Important

15

[Interpretation]

LRs 5-10 and 0.2-0.5

Small but Sometimes Important

16

Definition: Gold Standard

Accepted definition of disease and can dictate presence or absence of it

17

[Gold Standard]

Pulmonary TB

Chest X-Ray
Histopathology
Autopsy
Anti-Kochs
Sputum Culture

18

[Gold Standard]

Pneumonia

Chest X-Ray
Histopathology
Sputum Culture

19

[Gold Standard]

Systemic Lupus Erythematosus

Expert's Opinion

20

[Gold Standard]

Embolic CVD

CT Scan + 2D Echo

(Need Both)

21

Definition: Sensitivity

Probability of a positive test among diseased

22

Sensitive tests are more important for generalists or specialists?

Why?

Generalists

To not miss people with the disease

23

Definition: Specificity

Probability of a test being negative among non-diseased people

24

A positive test is more helpful for Specific or Sensitive tests?

Specific Tests

25

Specific tests are more important for generalists or specialists?

Why?

Specialists

To help confirm diagnosis

26

Definition: Accuracy

Proportion of people correctly diagnosed by tests as either having the disease or not having it

27

Differentiate:

(+) Predictive Value
(-) Predictive Value

( + ): Probability that patient has the disease given a + test result

( - ): Probability that patient does not have the disease given a - test result

28

Define: Kappa Statistics

Measures agreement beyond chance

29

[Interpretation]

K = 1 or 100%

Perfect Agreement

30

[Interpretation]

K > 0.80

Excellent Agreement

31

[Interpretation]

0.60 < K <= 0.80

Good Agreement

32

[Interpretation]

0.40 < K <= 0.60

Fair Agreement

33

[Interpretation]

0 < K <= 0.40

Poor Agreement

34

[Interpretation]

K = 0

Chance Agreement