Analytic Study Designs
Test the hypothesis.
Address the causation.
Nested Case Control
Disadvantages:
- Reduce precision due to sampling of controls
Advantages:
- Less expensive
- Efficient
Description:
the controls are sample of individuals who are at risk for the disease at each of the cases are matched with controls that do not have the disease
Case Cohort
Disadvantages:
- complicated statistical analysis
Advantages:
- possible to study multiple diseases
Description:
- cases are selected by those who have developed the disease of interest and before the controls
Cohort
Disadvantages:
- losses to follow up
- requires large samples
- expensive
- long time to complete
Advantages:
- find out incidence and rate
- establish cause and effect
- minimize selection and bias
Description:
-population exposure status is known from the start
- start with disease free people
- addresses disease at the follow up
- 3 cate: prospectively, retrospectively, ambidirectional
Case Control
Disadvantages:
- Low data quality
- difficult finding control group
Advantages:
- Good for studying rare conditions
- Look at multiple risk factors
- Establish relationship
Description:
-study that studies cases to controls
-Controls must be similar to the cases
-Known as retrospective study
Descriptive Study Designs
Describes the events. Answers the what, who, where. Generates the hypothesis
Cross-Sectional
Description:
- exposure & disease measured at the same time
- assesses prevalence of the outcome
Advantages:
- study nonfatal & chronic conditions
- measures
Disadvantages:
- relationship b/w exposure and disease may be difficult to establish
- Does not reflect a casual relationship
Ecological Studies
Description:
Data analyzed at the population or
group level rather than individuals.
Advantages:
- Easier
- Hypothesis is new
Disadvantages:
- Ecological fallacy-placing characteristics
of a group to every individual in that group
Case Series
Description:
Subjects common characteristics
Describes some aspect of disease treatment,
exposure, or diagnostic procedure
Advantages:
- Informative
- Characterize averages for disorder
Disadvantages:
- No cause/effect relationship
- Doesn't assess disease frequency
Case-Report
Description:
Detail
Generates Hypothesis
Single Cases
New findings/unique
Advantages:
- Find new diseases
- ID rare manifestations
-
Disadvantages:
- No generalization
- No cause/effect relationship
Observational Study Designs
