8) Diagnostic Test

Question 1

Sensitivity

Answer 1

• proportion of people with disease who test positive

Question 2

Specificity

Answer 2

Proportion of people with no disease who test negative

Question 3

Positive predictive value:

Answer 3

Proportion of people who test positive and have the disease

Question 4

Negative predictive value

Answer 4

Proportion of people who test negative that have no disease

Question 5

Spin Snout

Answer 5

• when a test has a high sensitivity, a negative test rules out a disease
• when a test has high specificity, a positive test rules in the disease

Question 6

Evaluating diagnostic test

Answer 6

typically cross sectional studies

Question 7

Verificatiion bias

Answer 7

• occurs when only a proportion of people with negative index test results has the reference standard done

Question 8

Validation

Answer 8

The index test is a new test and the diagnostic threshold has been determined only when using this data set
- the index test is a prediction based on a large number of parameters and the test accuracy has been determined using this training set only

Question 9

What is Random Error?

Answer 9

Poo