Screening

Question 1

Types of screening based on population screened?

Answer 1

Mass
High risk
Multiphasic

Question 2

Whole population screening called as ?

Answer 2

Mass screening

Question 3

Level of prevention in prescriptive screening?

Answer 3

Secondary

Question 4

Level of prevention in presumptive screening?

Answer 4

Primary level

Question 5

What is screening time?

Answer 5

1st possible point of diagnosis to critical point of diagnosis

Question 6

Lead time?

Answer 6

1st possible point of diagnosis to usual point of diagnosis

Question 7

Good screening tool characteristics?

Answer 7

Long lead time
Short screening time

Question 8

Characteristics of 1st possible point of diagnosis?

Answer 8

Highly interventional
Ideal
Expensive

Question 9

Critical point of diagnosis characteristics?

Answer 9

Optimum
Affordable

Question 10

Lead time bias?

Answer 10

Investigation with long lead time :
1. Virtual lowering of mortality rates
2. No changes in treatment outcome or absolute death rates

Question 11

Criteria for good screening tool?

Answer 11

Affordable
Approachable/available
Acceptable
Valid, accurate, precise

Question 12

Define validity, accuracy, precision?

Answer 12

Validity: Getting desired results within defined range
Accuracy: Closeness to true value
Precision: repeating/ reproductive of result

Question 13

Define sensitivity and specificity?

Answer 13

Sensitivity: probability of having tested positive out of total diseased population
Specificity: probability of having tested negative out of total healthy population

Question 14

Define false positive error rate and false negative error rate.

Answer 14

FPER: Tested positive out of healthy
FNER: TESTED NEGATIVE OUT OF Diseased POPULATION

Question 15

Positive predictive values PPV?

Answer 15

Having disease out of tested positive

Question 16

Negative predicted value NPV?

Answer 16

No disease out of tested negative population

Question 17

False positive error rate formula?

Answer 17

FPER = 1-Specificity

Question 18

False negative error rate formula?

Answer 18

FNER = 1-Sensitivity

Question 19

Seriousness of error?

Answer 19

FP>FN or
T1>T2 or
Alpha> beta

Question 20

False positive is related to and false negative is related to?

Answer 20

Type 1 and alpha errors in FP
Type 2 and beta errors in FN

Question 21

Likelihood ratio ? + or -?

Answer 21

LR+ : Sn/(1-Sp)
LR- : (1-Sn)/Sp

Question 22

Screening test vs diagnostic test requirements?

Answer 22

Screening: increased sensitivity & decreased false negative
Diagnostics: increased specificity & decreased false positive

Question 23

Odds ratio?

Answer 23

No. Of times an event is likely to happen
———————————————————-
No. Of times an event is unlikely to happen