Case-Control (Retrospective) Research Design
Purpose
The purpose of this design is to provide exploratory information through the use of clinical data from hospitals, clinics, and physicians’ records.
Extracting information from the patients’ charts.
Components
Two groups coming from the same population
One group has the disease under investigation (cases) and the second group are those individuals who do not have the disease under investigation – they can have any other disease but the disease being studied (control)
Compare groups to determine what characteristics differentiate from the patients between those with the disease and those without the disease.
Develop hypotheses
Identifying potential risk factors that are associated with the disease.
Example
In the late 1940s with case-control designs, it was discovered that smoking cigarettes was more common among lung cancer patients than among those who did not smoke cigarettes.
Strengths
Primarily used to investigate rare diseases because hospitals and clinical records contain the data
Clinical verification – data is not based on self-reports
a. Professionals clearly identify patients who have the disease under investigation and those patients who do not.
Relatively low cost
Relatively quick
Limitations
Poor generalizability to the general population because it comes from existing records (hospitals, clinics). Hospital records have poor generalizability because not everyone has access to a hospital (i.e.individuals with no insurance, distrust medical staff, lack on of knowledge, hard to get an appointment, language barriers, etc.).
Missing elements
a. Patient records may be incomplete with missing information.
