Screening

Question 1

search for unrecognized disease or defect by means of rapidly applied tests, examinations or other procedures in apparently healthy individuals

Answer 1

Screening

Question 2

sort out apparently well persons who probably have a disease from those who probably do not

Answer 2

Screening tests

Question 3

not intended to be diagnostic

Answer 3

Screening tests

Question 4

Screen the whole population

Answer 4

Mass screening

Question 5

Screen groups with specific exposures / risks

Answer 5

Selective / high risk screening /Targeted screening

Question 6

Screen groups with specific exposures / risks

Answer 6

Selective / high risk screening /Targeted screening

Question 7

variety of screening tests on same occasion

Answer 7

Multiphasic /multiple screening

Question 8

patients who consult health practitioners for a different reason/ condition

Answer 8

Case finding or opportunistic screening

Question 9

Criteria of Screening test

Answer 9

Acceptability

Reliability

Validity

Question 10

acceptable to the people at whom it is aimed at

Answer 10

Acceptability

Question 11

results obtained be replicated if the test is repeated

must give consistent results when repeated more than once on the same individual or material, under the same conditions

Answer 11

Repeatability /reliability

Question 12

Extent to which the test measures accurately what it purports to measure

Ability to distinguish between who has a disease & who does not

Answer 12

VALIDITY

Question 13

2 components of VALIDITY

Answer 13

Sensitivity & Specificity

Question 14

Ability of a test to identify correctly all those who
have the disease, i.e. “True positive”.

Answer 14

Sensitivity

Question 15

ability of a test to identify correctly all those who do not have the disease, i.e. “True negative”.

Answer 15

Specificity

Question 16

proportion of diseased people who were correctly identified as “positive” by the test

Answer 16

Sensitivity

Question 17

proportion of non diseased people who were correctly identified as“negative”by the test.

Answer 17

Specificity

Question 18

Proportion of patients who test positive, actually have the disease.

Answer 18

Positive predictive value

Question 19

Proportion of patients who test negative, actually do not have the disease.

Answer 19

Negative predictive value

Question 20

the ratio of the sensitivity of a test to the false-positive error rate of the test

Answer 20

likelihood ratio positive

Question 21

the ratio of the false-negative error rate divided by the specificity

Answer 21

likelihood ratio negative

Question 22

used in emergency situations, severe disease
where 2 or more - less sensitive tests are available, combining both would increase the sensitivity.

Answer 22

Simultaneous (parallel) testing

Question 23

Initially a less expensive, less invasive/less uncomfortable test is performed.
Those who screen positive are recalled for testing with a more expensive, more invasive/more uncomfortable test.
Reduce the problem of false positives.

Answer 23

Sequential (two stage) testing

Question 24

net gain in sensitivity

net loss in specificity

Answer 24

simultaneous testing

Question 25

net loss in sensitivity net gain in specificity

Answer 25

sequential testing

Question 26

screening test, should have

Answer 26

high degree of sensitivity

Question 27

confirmatory test, should have

Answer 27

high degree of specificity

Question 28

additional lead-time may not have changed the natural history of the disease or extended the longevity of life

Answer 28

Lead time bias

Question 29

interval by which the time of diagnosis is advanced by screening and early detection of disease compared to the usual time of diagnosis

Answer 29

Lead time

Question 30

point in natural h/o before which treatment is effective &/less difficult to administer

Answer 30

Critical point