Flashcards in Leccture 18 - Case-Control Studies Deck (10)
What is a case-control study?
-those with the disease of interest are the cases and those without are the controls
-group-assignment is based on disease status
-useful in studying rare diseases or outbreaks
-generates odds ratio
What type of ratio is a case-control study most useful for generating?
What is the scenario where the phrase “randomly selected” can be used but not indicate an interventional study?
-in a case-control study where there are more cases or controls than needed for the study so those observed are randomly selected
What are the strengths of case-control studies?
-good for assessing multiple exposures of one outcome
-useful in rare diseases
-useful in determining associations
-less expensive and time consuming
-avoid ethical issues
What should be taken into account when selecting controls for case-control studies?
-controls should be as equal as possible to cases but without disease
-should be picked regardless to exposure status
What is a case-crossover study design?
-case control study where subjects act as their own control
-look at patient before they were a case and assess what exposures they had in between that may be responsible for the change
What is a nested case-control study?
-a case-control study that comes out of a prospective study (such as cohort or interventional)
What are the types of sampling of controls in nested case-control studies?
-sample non-diseased individuals (survivors) AT THE END of a study
-sample non-diseased individuals AT THE START of a study
-sample non-diseased individuals DURING STUDY period AT SAME TIME case was diagnosed
What are the common types of bias affecting case-control studies?