What is a case in a case control study?

Asked By: Fadrique Soroeta | Last Updated: 11th February, 2020
Category: medical health cancer
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A case-control study is designed to help determine if an exposure is associated with an outcome (i.e., disease or condition of interest). First, identify the cases (a group known to have the outcome) and the controls (a group known to be free of the outcome).

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Correspondingly, what is an example of a case control study?

A case-control study is a retrospective study that looks back in time to find the relative risk between a specific exposure (e.g. second hand tobacco smoke) and an outcome (e.g. cancer). A control group of people who do not have the disease or who did not experience the event is used for comparison.

Also Know, what is a case control and cohort study? Introduction. Case-control and cohort studies are observational studies that lie near the middle of the hierarchy of evidence. These types of studies, along with randomised controlled trials, constitute analytical studies, whereas case reports and case series define descriptive studies (1).

Similarly, what does case control study mean?

A study that compares patients who have a disease or outcome of interest (cases) with patients who do not have the disease or outcome (controls), and looks back retrospectively 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

What are the limitations of a case control study?

The main limitations of case-control studies are:

  • 'Recall bias' When people answer questions about their previous exposure to certain risk factors their ability to recall may be unreliable.
  • Cause and effect.
  • 'Sampling bias'
  • Other limitations.

35 Related Question Answers Found

How many controls are in a case?

Case-Control Studies
The results suggest that investigators consider including more than five controls per case when either phi is greater than about 0.2 or Po is less than about 0.15.

How do you identify a case control study?

First, identify the cases (a group known to have the outcome) and the controls (a group known to be free of the outcome). Then, look back in time to learn which subjects in each group had the exposure(s), comparing the frequency of the exposure in the case group to the control group.

What is the purpose of a cohort study?

Cohort studies are a type of medical research used to investigate the causes of disease and to establish links between risk factors and health outcomes. The word cohort means a group of people. Prospective” studies are planned in advance and carried out over a future period of time.

How do you choose controls in a case control study?

Selection of the Controls
  1. The comparison group ("controls") should be representative of the source population that produced the cases.
  2. The "controls" must be sampled in a way that is independent of the exposure, meaning that their selection should not be more (or less) likely if they have the exposure of interest.

Is a case control study qualitative or quantitative?


Experiments done in a laboratory will almost certainly be quantitative. In a health care context, randomised controlled trials are quantitative in nature, as are case-control and cohort studies. Surveys (questionnaires) are usually quantitative .

What is the difference between a case control study and a cross sectional study?

cross sectional is prevalence study and useful to look at single point of time whereas case control study are used to study 2 groups cases(diseased) and controls (non-diseased) and to identify the risk factors between them . it looks back from the time of exposure and the occurrence of disease.

When would you use a case control study?

The casecontrol study design is often used in the study of rare diseases or as a preliminary study where little is known about the association between the risk factor and disease of interest. Compared to prospective cohort studies they tend to be less costly and shorter in duration.

What makes a good case control study?

A casecontrol study aims to derive a risk estimate for a particular factor of exposure (environmental or genetic) that is as close as possible to the estimate that would have been derived had a prospective cohort study been performed.

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 does cohort study mean?


A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time.

What are the 3 types of observational study?

Types of Observational Studies. There are three major types of observational studies, and they're listed in your text: cross-sectional studies, case-control studies, and cohort studies.

What type of study design is this?

Analytical observational studies include case””control studies, cohort studies and some population (cross-sectional) studies. These studies all include matched groups of subjects and assess of associations between exposures and outcomes.

What is case cohort study?

In a case-cohort study, cases are defined as those participants of the cohort who developed the disease of interest, but controls are identified before the cases develop. Case-cohort studies are very similar to nested case-control studies .

What are the different types of studies?

The main types of studies are randomized controlled trials (RCTs), cohort studies, case-control studies and qualitative studies.

What is a controlled study?


Controlled study. Definition: An experiment or clinical trial in which two groups are used for comparison purpose. More: In a controlled exposure study, one group of participants is exposed to a substance (e.g. a pollutant) while those in the "control" group are not.

What are the advantages and disadvantages of studying disease using a cohort study?

Disadvantages of Prospective Cohort Studies
You may have to follow large numbers of subjects for a long time. They can be very expensive and time consuming. They are not good for rare diseases. They are not good for diseases with a long latency.

What is an example of a cohort?

Examples of cohorts commonly used in sociological research include birth cohorts (a group of people born during the same period of time, like a generation) and educational cohorts (a group of people who begin schooling or an educational program at the same time, like this year's freshman class of college students).