Epidemiology Flashcards
How are proportions superior to counts?
Proportions allow you to look at percentages & allow you to compare the rates of illnesses in groups of different sizes. Counts are simple numbers & don’t allow this.
What is the difference b/w the natural history of disease & the clinical history of disease?
Natural history–progression of the disease w/o treatment.
Clinical History: progression of the disease w/ treatment.
What is clinical epidemiology?
With this study of illness you look @ the clinical outcomes of the disease/illness.
Where does descriptive epidemiology fall in the scientific method?
After asking the question & before forming a hypothesis.
What is a case control study? What general type of study is it? What are its advantages?
It is an observational study. It looks at ppl w/ or w/o a disease & retrospectively looks back at whether they were exposed to certain risk factors. They can look cheaply & quickly at association w/ multiple risk factors.
What is a cohort study? What general type of study is it? What are its advantages? How does it compare to a case control study?
Observational study.
Cheap, can see an association.
Different than case control b/c you look first at a group of people who have been exposed & those who haven’t & you study prospectively to see if they develop a given disease.
What is a randomized controlled trial considered? How does it compare to a cohort study?
It is considered experimental b/c the study determines if you are exposed or not exposed.
It is of course prospective & only really differs from a cohort study in that it is randomized.
What is a cross sectional study?
You kind of look at a population & describe the prevalence of a certain disease. it is observational.
What is temporality? Which study designs include this?
It is the assurance that the exposure preceded the disease. This is a component of studies that are prospective. This includes cohort studies & randomized clinical trials.
What is a type of study that only provides counts?
Case study. it is only descriptive.
What study designs lack temporality?
Case Control & Cross Sectional
Briefly explain phases 1-4 of the clinical trials.
Preclinical: animals tests, biological plausibility
Phase I: less than 30 volunteers; determine safety
Phase II: about 50 volunteers; determine safe dosage
Phase III: Randomized Clinical Trial–determine effectiveness
Phase IV: Observational Post Market Study, large study group
What are 3 important things to consider in determining causality?
Temporality
Biological Plausibility: can sometimes use animal tests
Dose Response: you should see a gradient b/w the effect & the amount of exposure
