Category - Case Control Studies

Case-Control Studies compare patients who have a disease or outcome of interest (cases) with patients who do not have the disease or outcome (controls). It looks back in retrospect to compare how frequently the exposure to a risk factor is present in each group to determine the relationship between the risk factor and the disease.

Case-control studies are observational because no type of intervention is attempted and no attempt is made to alter the course of the disease or condition. The goal is to determine the exposure of the risk factor of interest from each of the two groups of individuals retrospectively. These studies are designed to estimate odds and are also known as Retrospective Studies, & Case Referent Studies.

1. Case-control studies work backwards as they first identify diseased and non-diseased individuals, then ascertain the frequency of previous exposures.

2. Ideal characteristics for selecting cases is:

a. Select individuals who have the incident disease

b. Use a specific definition of the disease

Advantages: The advantages that case-control studies have include:

Answering questions that could not be answered from other studies
Studying rare conditions/diseases
Less time needed to conduct the study because the condition or disease has already occurred
Simultaneously look at multiple risk factors of the disease
Useful as initial studies to establish an association

Disadvantages: The disadvantages of a case-control study are:

Difficulty finding a suitable control group
Not good for evaluating diagnostic tests. Some cases have the condition and the controls do not.
Retrospective studies have problems with data quality because of the reliance on memory and people with a condition are more motivated to recall risk factors.