# My Study Stuff

## 22/01/2023

### Odds Ratio?

Filed under: Health — wypiwyg @ 7:37 PM

## odds ratio – text from: InterpretingOddsptversion.pdf

http://simp.ly/p/Thm4fd

The odds ratio is the “measure of association” for a case-control study. It quantifies the relationship between an exposure (such as eating a food or attending an event) and a disease in a case-control study. The odds ratio is calculated using the number of case-patients who did or did not have exposure to a factor (such as a particular food) and the number of controls who did or did not have the exposure.

The odds ratio tells us how much higher the odds of exposure are among case-patients than among controls. An odds ratio of
• 1.0 (or close to 1.0) indicates that the odds of exposure among case-patients are the same as, or similar to, the odds of exposure among controls. The exposure is not associated with the disease.

• Greater than 1.0 indicates that the odds of exposure among case-patients are greater than the odds of exposure among controls. The exposure might be a risk factor for the disease.

• Less than 1.0 indicates that the odds of exposure among case-patients are lower than the odds of exposure among controls. The exposure might be a protective factor against the disease.

The magnitude of the odds ratio is called the “strength of the association.” The further away an odds ratio is from 1.0, the more likely it is that the relationship between the exposure and the disease is causal. For example, an odds ratio of 1.2 is above 1.0, but is not a strong association. An odds ratio of 10 suggests a stronger association.

http://simp.ly/p/Thm4fd

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