Intro into Epidemiology Flashcards
What are epidemiological principles essential for understanding?
- spread of disease in populations, and how to manage this
- occurrence of complex diseases and productivity problems
- impact of disease on populations
What two sources of evidence should be used for decision making when practicing evidence based veterinary medicine?
Internal: your own clinical experience and expertise (your experience alone becomes narrow and may become outdated)
External: Evidence from other research (alone, this may be irrelevant without your clinical experience)
What is epidemiology?
The study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems
Veterinary epidemiology deals with the investigation of diseases, _______, and _______ in the animal populations
productivity and welfare
*it describes the frequency of occurrence of these health-related states/events and how dzs, productivity, and welfare are affect by different factors or determinants
What is the primary goal of veterinary epi?
To reduce the frequency of dz occurrence, enhance productivity, and improve animal welfare
What must you answer to describe the distribution of health related states/events? (4 Ws)
Who
what
when
where
study the natural history of the dz and describe the prognosis of the dz
What must you answer to identify determinants of health related outcomes?
WHY
Identify causes and risk factors of dz and health
Evaluate preventative and therapeutic measures
T/F: Veterinary epidemiology focuses very much on the individual
FALSE
Focus is on populations, herds, farms, shelters, etc
The clinical approach focuses on the ______
Individual
*success depends on the disease being known and correct diagnosis/or list of diagnoses
What is the epidemiological approach of thinking?
Focuses on groups
- Describes those individuals in a pop with dz and those with less dz
- Look for differences between the groups
- Apply measures to reduce contributing factors
** success without known the etiological agent
T/F: The best approach in vet med is to used a clinical and epidemiological approach combination
TRUE
Who is the “father of epi” and dz outbreak did he work on?
John Snow
Cholera outbreak in London 1853 - he investigated the cases of cholera deaths and where they received their water supply from
Fill in the blanks (descriptive or analytical)
John Snow started with _____ epi, obtaining information on the numerator (# of cholera deaths) and the denominator (# of people supplied with water)
Then he used ______ epi to compare the death rates of cholera in the two different areas
- descriptive
2. Analytical
What form of epidemiology describes the disease or other health related events (answering the What, Who, When, and where)?
Descriptive epi
What form of epi determines if there is an association between an exposure and outcome in a population and how strong the association is (the WHY)?
Analytical
In descriptive epi, what is the case definition?
Standard criteria for categorizing an individual as a case
**avoids subjectivity
This is important in answering the WHAT: the health/production/or welfare issue of concern
How do you answer the WHEN when using descriptive epi?
Can be looked at many different ways pending on the dz/health issue you are looking at.. could be:
- Changing or stable rates of dz
- Clustered in time or evenly distributed
- Single point source or intermittent exposure
- Seasonal variation
What are some exampled of WHERE when using descriptive epi?
- geographic location - restricted or widespread
- relation to a food or water supply
- Clustered or evenly distributed
*one room or whole barn
etc
What are some limitations of descriptive epi?
- cannot formally ID associations between exposure and outcome
- cannot infer causality
PRO - can be useful to generate hypotheses for future testing/studies
Case reports, Case series, and cross sectional studies are all examples of what kind of epidemiological studies?
Descriptive
_______ epidemiology is aimed at identifying and determining the strength, importance, and statistical significance of associations between exposures and health related outcomes
Analytical
What is an association?
There is an association between an exposure and an outcome when they are dependent on one another
*an identifiable relationship between an exposure and outcome
T/F: Epi determines the cause of a disease in a give individual
FALSE
It determines the relationship or association between a given exposure and the frequency of disease in populations
Causation implies that there is a ____ mechanism that leads from the exposure of the disease
True
Who and what are involved in the epidemiological triad?
Host
Agent
Environment
This is a model of disease causation but is not adequate for diseases that appear to have multiple contributing causes without a single necessary one
What model of disease causation is used to represent a disease caused by multiple factors; when a host is exposed to all these factors (not necessarily at the same time), disease occurs
Rothman’s model (casual pies)
*individual factors are component causes - all those combined = sufficient cause of disease
What is the Bradford-Hill criteria used for?
Determining whether an association is causal
Criteria includes: Temporal relationship Strength of association Dose-response relationship Replication of findings Biological plausibility Consideration of alternative explanations Cessation of exposure Specificity of the association Consistency with other knowledge
