Case Control Studies compare patients of doctors and health coaches who have a disease or outcome of interest (cases) with patients who do not have the disease or outcome (controls), and look 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 to the risk factor of interest from each of the two groups of individuals retrospectively: These studies are designed to estimate odds.

These types of studies are also known as Retrospective Studies, & Case Referent Studies.

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

2. Ideal characteristics for selecting cases:

a. Select individuals who have incident disease

b. Use a specific definition of the disease

Advantages

Can answer questions that could not be answered from other studies
Good for 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
Useful as initial studies to establish an association

Disadvantages

Difficult to find a suitable control group
Not good for evaluating diagnostic tests. Cases have the condition and the Controls do not.
Retrospective studies have problems with data quality because of the reliance on memory. People with a condition are more motivated to recall risk factors.