L04: Secondary Prevention

Question 1

What is the definition of screening

Answer 1

Identifying apparently healthy people who may be at risk of a disease

Question 2

Why is screening beneficial

Answer 2

It leads to early detection of disease and early treatment to reduce complication

Question 3

What are the ways we can screen

Answer 3

Questionaire
Examination
Lab test
Imaging

Question 4

After screening what are the 4 groups of results people are defined into

Answer 4

True negative
True positive
False negative
False positive

Question 5

What is a true negative

Answer 5

Someone who does not have the disease and shows as negative in the test

Question 6

What is a false negative

Answer 6

Someone who does have the disease but shows as negative on the test

Question 7

What is a true positive

Answer 7

Someone who has the disease and tests as positive on the test

Question 8

What is a false positive

Answer 8

Someone who doesn’t have the disease but shows as positive on the test

Question 9

What does sensitivity mean

Answer 9

The rate of true positive

Question 10

What is the equation for sensitivity

Answer 10

(True positive)/ all positive i.e false positive and false negative

Question 11

What is a specificity

Answer 11

The rate of true negative

Question 12

What is the equation for specificity

Answer 12

True negative/(true negative+ false positive)

Question 13

When is the sensitivity more useful to use

Answer 13

When the result is negative

Question 14

When is a specific test more useful

Answer 14

When the result is positive

Question 15

What is a predictive value look at

Answer 15

The likely hood of you testing positive and having the disease to the likelihood you testing negative and not having the disease

Question 16

What do predictive values depend on

Answer 16

Prevalence of the disease

Question 17

Is a screening test and a screening programme the same thing

Answer 17

No

Question 18

What is a screening programme

Answer 18

A systematic process that sends the invitation to apparently healthy individuals they further investigate,assess and diagnose those who are positive.

Question 19

What are the 3 biases that can occur in screening

Answer 19

Volunteer bias
Lead time bias
Length bias

Question 20

What is a volunteer bias

Answer 20

People who attend to screening have a low risk of the disease compared to those who do not attend

Question 21

What is a lead time bias

Answer 21

The time by which diagnosis is advanced because of screening so it is an apparent increase in survival

Question 22

What can lead time bias result in

Answer 22

The same survival rate but the patient who got diagnose before is aware of the illness for more years

Question 23

What is length time bias

Answer 23

Those with a slow progressive disease are more likely to be detected by screening than those who have a rapidly progressive disease

Question 24

What are the factors that influence screening policy

Answer 24

Evidence
Values
Commercial interest

Question 25

What are the criteria’s for assessing the appropriateness of implementing a screen programme

Answer 25

1) the condition: history has to be understood and primary prevention has to be implemented
2) the test: has to be suitable and valid
3) the intervention: has to have an effective treatment and policy on who we treat
4) screening programme: clinically, socially and ethically acceptable, the benefits outweigh the harms
5) implementation of programme: clinical management and patient outcomes should be optimised