Week 5

Question 1

What are the different types of biomarkers? (5)

Answer 1

Extrinsic- such as lifestyle
Intrinsic- such as physical (signs and symptoms), psychological (scores, scales and questionnaires), and laboratory (physiological, biochemical, immunological….)

Question 2

What can be predicted or identified with biomarker measurements? (3)

Answer 2

Predicting disease
Identifying disease
Treatment

Question 3

What is biomarker validation and how can this be done? (3)

Answer 3

Optimising reproducibility and accuracy of analytical method
To ensure validation:
Select appropriate method for biomarker measurement
Standardise technique, conditions, processing

Question 4

What is the difference between sensitivity and specificity? (2)

Answer 4

Sensitivity: smallest amount of a variable that can be measured

Specificity: ability of a measurement to detect the variable rather than any other

Question 5

What is the difference between accuracy and precision? (2)

Answer 5

Accuracy: how close a measurement is to a true or accepted value

Precision: how close measurements of the same value are to each other

Question 6

What is the difference between repeatability and reproducibility? (2)

Answer 6

Repeatability: measurements performed under the same conditions

Reproducibility: measurements performs under different conditions

Question 7

What qualities make a good biomarker? (4)

Answer 7

Measurable
Little to no variability
Sizeable signal to noise ratio
Change promptly and reliably, in response to changes in its condition or therapy

Question 8

What is biomarker qualification?

Answer 8

The process of linking a biomarker with biological processes and clinical endpoints

1) Exploratory- some indication of disease mechanism or treatment response
2) Probable surrogate- well validated measurement with evidence linking the marker to clinical or intermediate endpoint
3) Known surrogate- well validated measurement with strong evidence, widely accepted