What statistics is used in case control studies?
What statistics is used in case control studies?
Case control method is most efficient, for the study of rare diseases and most common diseases. Other measures of association from case control studies are calculation of odds ratio (OR) and risk ratio which is presented in Table 2.
What is the reason that the odds ratio is instead preferred in a case-control study for a disease?
The odds ratio tells us how strongly the exposure is related to the disease state. An odds ratio of greater than one implies the disease is more likely with exposure. An odds ratio of less than one implies the disease is less likely with exposure and thus the exposure may be protective.
What is the source population in a case-control study?
Risk ratio (RR): the likelihood of a particular health outcome occurrence among persons exposed to a given risk factor divided by the corresponding likelihood among unexposed persons. Source population: the population out of which the cases arose. 1.
How do you choose controls for a case-control study?
Selection of the Controls
- The comparison group (“controls”) should be representative of the source population that produced the cases.
- 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.
How do you collect data in a case-control study?
Five steps in conducting a case-control study
- Define a study population (source of cases and controls)
- Define and select cases.
- Define and select controls.
- Measure exposure.
- Estimate disease risk associated with exposure.
- Confounding factors.
- Matching.
- Bias.
Is case-control study longitudinal?
Longitudinal and cohort studies follow the same group of individuals over time. Case-control studies include people with a disease or other condition and a suitable control or reference group. …
Why can’t you calculate risk in case-control study?
In a case-control study there is no “follow-up” period. In a case-control study, you cannot measure incidence, because you start with diseased people and non-diseased people, so you cannot calculate relative risk. The case-control design is very efficient.
What are case-control studies best for?
Case-control studies have specific advantages compared to other study designs. They are comparatively quick, inexpensive, and easy. They are particularly appropriate for (1) investigating outbreaks, and (2) studying rare diseases or outcomes.
What is control in case-control study?
A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls).
What is the main purpose of selecting controls in a case-control study?
The purpose of the control group is to determine the relative size of the exposed and unexposed components of the source population.
What are the advantages and disadvantages of case control studies?
Advantages and Disadvantages of Case-Control Studies. Advantages: They are efficient for rare diseases or diseases with a long latency period between exposure and disease manifestation. They are less costly and less time-consuming; they are advantageous when exposure data is expensive or hard to obtain.
What is the difference between case control and cohort study?
On the other hand, a case-control study is a research design used by researchers where the research begins with an outcome to comprehend the cause. One key difference between cohort and case-control study is that the cohort study is prospective while the case-control study is retrospective.
How to design a case control study?
In theory, the case-control study can be described simply. 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 a cohort or case control study?
Case–control study versus cohort on a timeline. “OR” stands for “odds ratio” and “RR” stands for “relative risk”. A case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute.
