Epi Final Flashcards
Purpose of Analytical Studies?
(2)
- ID & explain the cause of dz
- numerically assess risk factors
3 parts of an Analytical Study?
- Data collection
- Data analysis
- Data interpretation
Study type that compares dz occurrence between “exposed” & “non-exposed”
Cohort study
2 Strengths of Cohort Studies
- Rare exposure
- can examine multiple outcomes of a single exposure
Weaknesses of Cohort Study
(2)
- Not good for rare dz.
- time consuming if there is a long period between exposure & dz.
Prospective Cohort follows groups from _______ to ________.
present to future
Strengths of Prospective Cohorts
(3)
- measure Incidence
- describes temporal relationships
- collect data on possible confounders
Weaknesses of Prospective Cohorts?
(3)
- Expensive & long
- Lack of follow-up can affect validity
- Requires a large # of subjects
Retrospective Cohort follows subjects from _______ to _______.
present to past
Strengths of Retrospective Cohorts
(3)
- data is already present
- cheap
- easy to perform
Weaknesses of Retrospective Cohorts
(2)
- Need good records → confounders
- Selection bias
Relative Risk looks at what?
how many times more/less likely exposed individuals are to get the dz. relative to non-exposed individuals
How do you calculate RR?

Purpose of Cofidence Interval (CI)?
allows you to determine whether or not the RR/OR can be deemed statistically significant
When is the result said to be statistically significant?
(in regards to the CI)
- if the CI falls entirely on either side of the null value (1.0)
- has be 95% or higher
_______ are study subjects who have the disease of interest in Case-Control Studies.
Cases
What is the purpose of Case-Control Studies?
compare frequency of exposure factors in cases w/ dz and cases w/o dz.
_______ are subjects who are dz free at the time of selection in Case-Control Studies.
Controls
Where does Case Selection come from?
- all cases in a defined population or from the general population
- often more convient
Controls selected from CCS should be __________ to cases in every respect except _______.
- identical
- disease
How do you calculate Odds Ratio (OR)?

Which study uses OR?
Case-Control Studies
4 Strengths of Case-Control Study?
- Rare dz.
- Multiple exposure
- cheap & fast
- Small # of subjects
4 Weaknesses of Case-Control Studies?
- No Incidence or Prevalence
- Bias→ recall, selection, information, misclassification
- Difficult to establish temporal relationships
- Cofounding




