Population Based Screening

Question 1

Define screening

Answer 1

Early detection of disease, precursors& susceptibility to disease in individual Who don’t have any signs of disease.

Question 2

List 4 aims of screening

Answer 2

① 2 detect early stages of disease so tx can be given.
② reduce disease burden
③ 2 detect disease predisposition so individual can be remove d from exposure 2 specific hazards.
④ classify people 2 likelihood of having particular disease

Question 3

Covid screening 2 whole popu. Or to high risk groups

This is what type of screening?

Answer 3

Mass screening

Question 4

De use of variety of screening tests on de same occasion

This is ___ screening

Answer 4

Multi- phasic

Question 5

Define targeted screening & give eg.

Answer 5

Screening of groups with specific exposure. Eg. Level of lead in blood on workers in lead foundaries

Question 6

Find out Covid case accidentally by performing routine procedure
This is what kind of screening?

Answer 6

Opportunistic screening

Question 7

5 uses of screening test

Answer 7

①4 case detection of unrecognized disease.
② 4 de control of disease
③ research purposes
④ 2 estimate de incidence of disease
⑤2 estimate de prevalence of disease.

Question 8

Define validity & give 2 components of it

Answer 8

• How close it is 2 de truth

Sensitivity t specificity

Question 9

Define sensitivity & Show de formula

Answer 9

• Frequency of persons who have disease 2 be identified as (+)
• a/a+c

Question 10

Define specificity & show de formula

Answer 10

Frequency of persons who do not have disease 2 be identified by test (-) ve
- D/b+d

Question 11

Probability that if de test is (+) ve pt. Truly have de disease.

Answer 11

(+) ve predictive value

-a/a+c

Question 12

(-) ve predictive value

Answer 12

Probability that when de test is (-)ve, pt. Does not truly have de disease.
-d/b+d

Question 13

False positive percentage:

Answer 13

Fp% =(b/a+b)x100

Question 14

False negative percentage :

Answer 14

(C/c+d)x100

Question 15

Criteria 4 mass screening prog.

Answer 15

① condition sought should be impo. Public health prob.
② screening test should be effective
③ Test should be acceptable 2 de popu.
④ there should be a strategy on whom 2 treat as pt.

Question 16

What are 3 possible biases in screening prog?

Answer 16

① lead time bias
② length bias
③ over diagnosis bias