Diagnostic test/prev/incid

Question 1

Sensitivity definition?

Answer 1

the probability of a diseased person testing positive

Question 2

Specificity definition?

Answer 2

the probability of a non-diseased person testing negative

Question 3

PPV definition?

Answer 3

the probability that person who has a positive test, actually has the disease

Question 4

NPV definition?

Answer 4

the probability that person who has a negative test, actually does not have the disease

Question 5

Positive likelihood ratio definition?

Answer 5

a ratio representing the likelihood of having the disease given a positive result

Question 6

Negative likelihood ratio definition?

Answer 6

a ratio representing the likelihood of having the disease given a negative result

Question 7

sensitivity formula?

Answer 7

TP/ (TP+FN)

Question 8

specificity formula?

Answer 8

TN/ (TN+FP)

Question 9

PPV formula?

Answer 9

TP/ (TP+FP)

Question 10

NPV formula?

Answer 10

TN/ (TN+FN)

Question 11

+LR formula?

Answer 11

Sensitivity/ (1-specificity)

Question 12

-LR formula?

Answer 12

(1-sensitivity)/ specificity

Question 13

Sensitive tests have many ….

Answer 13

FP

Question 14

Specific tests have few ….

Answer 14

FP

Question 15

SN-N-OUT?

Answer 15

sensitive tests, if negative, rule out the disease

Question 16

SP-P-IN?

Answer 16

specific tests, if positive, rule in the disease

Question 17

sensitivity. value approaching 100 proc. is desirable for ruling OUT DISEASE and indicates a low FN rate

Answer 17

.

Question 18

specificity. value approaching 100 proc. is desirable for ruling IN DISEASE and indicates a low FP rate

Question 19

What test for screening?

Answer 19

sensitivity

Question 20

what test used for confirmation after a positive screening test?

Answer 20

specificity

Question 21

increasing prevalence of disease increases ……

Answer 21

PPV

PPV varies directly to prevalence

Question 22

decreasing prevalence of disease increases ……

Answer 22

NPV

NPV varies inversely to prevalence

Question 23

LR +/- ranges?

Answer 23

LR+ > 10 and/or LR- <0,1 indicate a very usedul diagnostic test

Question 24

Incidence. definition?

Answer 24

Measure of NEW cases that develop in a population over a certain period of time

Question 25

Prevalence. definition?

Answer 25

Measure of the TOTAL number of cases (new and old) measured at a particular point in time

Question 26

Incidence. 2 points to remember?

Answer 26

2. Measuring incidence:

a. Make sure you define the TIME PERIOD during which new cases is counted

b. Make sure you include only the population at risk of acquiring the disease

Question 27

prevalence incr –> PPV?

Answer 27

incr

Question 28

prevalence decr –> PPV?

Answer 28

decr

Question 29

prevalence incr –> NPV?

Answer 29

decr

Question 30

prevalence decr –> NPV?

Answer 30

incr

Question 31

Precision (reliability)? patikimumas. definition?

Answer 31

The consistency and reproducibility of a test.

Absence of random variation in a test

Question 32

Accuracy (validity)? pagrįstumas. definition?

Answer 32

the trueness of test measurement.

The absence of systematic erroc or bias in test.

It means how much the test results agree with the gold standard test.