Epidemiology and Biomarkers Flashcards
Epidemiology is…..
The study of the distribution and determinants of health related events and the application of this study to the control of diseases and health problems
What are the aims of epidemiology?
- Revealing unbiased relationships between exposures to mortality or morbidity
- Identify causal relationships between these exposures and outcomes
What are the differences between observational and experimental studies?
Observational - observe from the sidelines so nature takes its course e.g. follow smokers to see how many develop lung cancer
Experimental - control all the factors entering a certain study e.g. clinical trials
What are the 3 types of studies?
- Case series
- Cohort study
- Case-control study
What is a case series?
Qualitative study, single patient or a small group of patients, all have a similar diagnosis or statistical factor
What is a case-control study?
Retrospective study, subjects selected based on their disease status
What is a cohort study?
Subjects selected based on their exposure status and followed through time
What are the 3 main types of neurotrauma?
Traumatic brain injury, spinal cord injury, stroke
What is the leading cause of Injury related morbidity in neurotrauma?
Motor vehicle accidents
What is the main problem currently with epidemiological studies in neurotrauma?
Need for a global agreement on variable collection to prevent fragmentation of studies
What is a biomarker?
A biological molecule found in blood, other bodily fluids or tissues that is a sign of a normal or abnormal process or of a condition or disease
What are the properties of an ideal biomarker?
Safe and easy to measure Cost efficient to follow up Rapid return of results Modifiable with treatment Consistent across gender and ethnic groups
What is the strategy for biomarker discovery?
Initially start with a large number of analytes and a small number of samples in the discovery phase. Use a mixed. approach to identify a smaller pool of potential biomarkers. These are then tested on a pool of samples which increases in size as you moved through the validation phase of clinical validation and regulatory approval.
Why do you start with a small amount of samples in the discovery phase and end with a larger amount of samples in the validation phase in biomarker discovery?
Techniques used in the discovery phase such as proteomics are very expensive and so a small number or samples are used to reduce cost. Methods used in the validation phase are much cheaper and so more samples can be used
Examples of high throughput technologies used in biomarker discovery
Genomics - genome sequencing Transcriptomics - microarray Proteomics - mass spectrometry Metabolomics - NMR Imaging
