A case-control study is designed to help determine if an exposure is associated with an outcome (i.e., disease or condition of interest). ... By definition, a case-control study is always retrospective because it starts with an outcome then traces back to investigate exposures .
What is the difference between a retrospective cohort study and a case-control study?
While retrospective cohort studies try to compare the risk of developing a disease to some already known exposure factors, a case-control study will try to determine the possible exposure factors after a known disease incidence .
What is a retrospective case study?
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.
What is a retrospective case-control observational study?
Retrospective studies “look back” in time contrasting with prospective studies, which “look ahead” to examine causal associations. Case-control study designs are also retrospective and assess the history of the subject for the presence or absence of an exposure .
Is case-control study prospective or retrospective?
Case-control studies are retrospective and cannot therefore be used to calculate the relative risk; this a prospective cohort study. Case-control studies can however be used to calculate odds ratios, which in turn, usually approximate to the relative risk.
What is an example of a retrospective study?
Retrospective example: a group of 100 people with AIDS might be asked about their lifestyle choices and medical history in order to study the origins of the disease . ... Prospective example: a group of 100 people with high risk factors for AIDS are followed for 20 years to see if they develop the disease.
What is the purpose of retrospective study?
Retrospective studies may be either cohort or caseecontrol studies and have four primary purposes: (1) either as an audit tool for comparison of the historical data with current or future practice , (2) to test a potential hypothesis regarding suspected risk factors in relation to an outcome, (3) to ascertain the sample ...
What is an example of a case-control study?
For example, in a case-control study of the association between smoking and lung cancer the inclusion of controls being treated for a condition related to smoking (e.g. chronic bronchitis) may result in an underestimate of the strength of the association between exposure (smoking) and outcome.
Does a cohort study need a control group?
Cohort studies differ from clinical trials in that no intervention, treatment, or exposure is administered to participants in a cohort design; and no control group is defined. ... The study is controlled by including other common characteristics of the cohort in the statistical analysis.
What type of study is a retrospective cohort study?
Retrospective cohort studies are a type of observational research in which the investigator looks back in time at archived or self-report data to examine whether the risk of disease was different between exposed and non-exposed patients.
How can you tell the difference between a prospective and retrospective study?
- In prospective studies, individuals are followed over time and data about them is collected as their characteristics or circumstances change. ...
- In retrospective studies, individuals are sampled and information is collected about their past.
Is a retrospective cohort study a case-control study?
Retrospective cohort studies are NOT the same as case-control studies . ... Therefore, cohort studies are good for assessing prognosis, risk factors and harm. The outcome measure in cohort studies is usually a risk ratio / relative risk (RR).
What level of evidence is a retrospective study?
For a retrospective cohort study, Level of Evidence = III .
What is an example of a prospective study?
Prospective Cohort Studies: ... The Framingham Heart Study, the Nurses Health Study , and the Black Women’s Health Study are good examples of large, productive prospective cohort studies. In each of these studies, the investigators wanted to study risk factors for common chronic diseases.
Are case-control studies retrospective?
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.
Why are case-control studies good?
A case-control study is a good tool for exploring risk factors for rare diseases or when other study types are not feasible . ... The investigator can then use the data from the case-control study to focus on a few of the most likely causative factors and develop additional hypotheses or questions.
