Epidemiologic Approach Flashcards
Epidemiology
The study of the distribution and determinants of health-related states or events (including diseases) in specified populations
application of this study to the control of health proglems
Descripitive Studies
Describes the occurrence and distribution of one or more variables in a population, group, or sample
* summarize disease or health over time
no hypothesis to test, often first studies done
Analytical study
measures the relationship or association between two variables, usually a risk factor and an outcome
tests a hypothesis “why did this occur?”
What factors/questions are analyzed in descriptive studies
- who gets sick?
- where are cases occurring?
- when are cases occuring?
- how are cases connected?
- how big is the problem?
Identification of connections between cases of disease is often based on _____
disease transmission
* direct contact
* respiratry
* fecal-oral
* vectorborne
* water/food
What are the 3 determinants of disease (epidemiology triad)?
risk factors or exposures
- host
- agent
- environment
What type of information is summarized in epidemic cuves?
- type of temporal pattern
- incubation pattern
- state of epidemic
- case counts
Measurement data
quantitative
variables that are measured and defined in numbers (weight, PCV, age, titers, survival time, etc.)
What value is analyzed with measurement data?
mean
Count data
categorical or qualitative
variables that are put into categories (breed, sex, positive/negative, old/young, healthy/sick/dead)
What values are measured with count data?
incidence and/or prevalence
Incidence
number of new cases during a specific interval
new cases/population at risk
Prevalence
proprotion of animals with a disease at a single point in time
all current cases/population at risk
Case fatality rate
measures disease severity and prognosis over the course of the disease
