My notes Block 10

Question 1

What are some possible reasons for opposing vaccines?

Answer 1

Disease is not serious
Disease is uncommon
Vaccine is ineffective
Vaccine is unsafe
Other methods of disease prevention are better

Question 2

Why is ethical reasoning important?

Answer 2

To be able to understand and evaluate arguments
To know when to challenge others views
Help you make right decision
Explain and justify decision to others

Question 3

An argument needs to be…

Answer 3

Logical
Valid
Sound

Question 4

What makes an argument valid?

Answer 4

Conclusion must follow on logically from the premises

Question 5

What makes an argument sound?

Answer 5

The argument has to be both valid and all the premises have to be true

Question 6

What is the sensitivity of a test?

Answer 6

True positives- Calculated by Number of true positives /all those with disease

Question 7

What is the specificity of a test?

Answer 7

True negatives- Calculated by Number of true negatives/ all those without disease

Question 8

What is the positive predictive value?

Answer 8

Number of true positives/ all those who test positive

Question 9

What is the negative predictive value?

Answer 9

Number of true negatives / All those who tested negative

Question 10

What are likelihood ratios?

Answer 10

Likelihood ratio for positive test is calculated by chance you test positive if ill / chance you test positive if well. The larger the number, the greater the likelihood you have the disease if you test positive.

Likelihood ratio for negative test is calculated by chance you test negative if ill / chance you test negative if well. The smaller the number result, the less chance you have the disease if you have tested negative

Question 11

What is screening?

Answer 11

The systematic application of a test to identify individuals at sufficient risk of specific disease to warrant further action

Question 12

Screening must have what 4 things?

Answer 12

Must be for a specific condition
Must have a test for that condition
Must have a treatment if the condition is found
Must have a programme in place

Question 13

What is length time bias?

Answer 13

The time you have the disease before it becomes symptomatic

Screening is good for conditions with a long length bias

Question 14

What is lead time bias?

Answer 14

Artificially longer survival time as condition was found sooner, but actually just knew they had the disease for longer

Question 15

How to decide on which conditions get a screening programme?

Answer 15

Needs to be an important health problem
Need to know the epidemiology and cause of disease well
Cost effective primary prevention implemented
Test needs to be sensitive and specific
Testing needs to be uninvasive and acceptable
Have evidence that early treatment leads to better outcomes