What is a retrospective case-control study?
Case-control studies are retrospective. They clearly define two groups at the start: one with the outcome/disease and one without the outcome/disease. They look back to assess whether there is a statistically significant difference in the rates of exposure to a defined risk factor between the groups.
Is a retrospective cohort study a case-control study?
This study is labeled as ‘case-control’, but it is actually a retrospective cohort study. Cohort studies follow groups defined by different exposures and observe the incidence of the outcomes. In the retrospective cohort design, the researcher starts the study at the time follow-up has already been completed (3).
What is a retrospective case series?
A retrospective case series is the description of a group of cases with a new or unusual disease or treatment. With a case-control study, cases with and without the condition of interest are identified, and the degree of exposure to a possible risk factor is then retrospectively compared between the 2 groups.
Why is cohort better than Case-Control?
Cohort studies work well for rare exposures–you can specifically select people exposed to a certain factor. But this design does not work for rare diseases–you would then need a large study group to find sufficient disease cases. Case-control studies are relatively simple to conduct.
Why is a case-control study referred to as a retrospective study?
By definition, a case-control study is always retrospective because it starts with an outcome then traces back to investigate exposures. When the subjects are enrolled in their respective groups, the outcome of each subject is already known by the investigator.
Is retrospective and case-control study same?
What is the difference between case-control and case series?
A case-series is just a series of cases. For example, a physician might encounter a series of patients who all have the same disease. The difference between a retrospective case series and a retrospective case-control is that the case series lacks a control group. As such, it is a much weaker design than case-control.
What is the main limitation of a case series?
In conclusion, a case series can be prone to bias, limiting its generalisability to larger populations of patients. However, a well-designed case series can provide information that allows hypotheses to develop, leading to further advanced studies.
What is the difference between cohort and case control?
Whereas the cohort study is concerned with frequency of disease in exposed and non-exposed individuals, the case-control study is concerned with the frequency and amount of exposure in subjects with a specific disease (cases) and people without the disease (controls).