Case-Control Study Design
What is matched pairs or individual matching?
In a study, each case is personally linked to a particular individual control. This approach is common in. genetic studies that link each case to a genetic sibling or other close genetic relative for analysis.
True or False: both cases and controls are asked the same set of questions about past exposures.
True
True or false: all cases must have the same disease, disability, or other health-related condition, and the study's case definition must specify exactly what characteristics must be present or absent for a person to be deemed a case.
True
True or false: case-control studies are able to examine odds of exposure among the disease and the not diseased
True
True or false: overmatching may result in a statistical bias that obscures the relationship between an exposure and the disease
True
True or False: some studies use no matching
True. They simply assume that similar inclusion and exclusion criteria for cases and controls will result in case and control populations that have similar distributions that may be cofounders of the association between the key exposure and the disease.
What is a contingency table or crosstab?
a row-by-column table that displays the counts of how often various combinations of events happen
What is bias?
a systematic error in the design, conduct, or analysis of a study that can cause the results of a study not to accurately reflect the truth about the source population
What action is key to minimize the risk of misclassification bias?
adhering to strict definitions for what constitutes a case and what constitutes a control.
What type of statistic is used to identify likely risk factors?
an odds ratio
What is frequency or group matching?
ensures comparable. case and control populations. Can be used to identify two, three, or more controls for each case. The goal is to recruit a control population that is similar to the case population.
What should an effective control definition do?
spell out all of the eligibility criteria for members of the comparison population
What does a case- control study compare?
the exposure histories of people with and without a particular disease in order to identify likely risk factors for the disease
What is an odds ratio (OR)?
the main measure of association for case-control studies, compares the odds of exposure among cases to the odds of exposure among controls
What is a two-by-two table?
used to compare two dichotomous (yes/no) variables
When does recall bias occur?
when cases and controls systematically have different memories of the past
How are individual participants in a case-control study selected?
They are selected for inclusion in the study based on their disease status.
True or false: case control studies are able to estimate rates of disease among the exposed and unexposed
False- due to the study population usually not representing a community as a whole
True or False: A case-control study is often NOT the best study approach for identifying possible risk factors for a disease
False- it is often the best study approach for this!
How are participants in the case-control study grouped?
Participants with the disease of interest are classified as cases. Those without the disease are classified as controls.
What characteristics should a case definition include?
person, place, and time (PPT)