*As I said before, in a case control study, the odds ratio is the exposure odds ratio, which is the odds of being exposed in the cases equals a divided by c.*Divided by the odds of being exposed in the controls or b divided by d.Data obtained from the cases and controls found that 218 cases and 45 controls consumed scallops.

*As I said before, in a case control study, the odds ratio is the exposure odds ratio, which is the odds of being exposed in the cases equals a divided by c.*

Under certain conditions, we can obtain a valid estimate of the rate ratio risk ratio using the odds ratio. So the ratio of controls to cases is not biologically or substantively meaningful.

But we won't go into those conditions for this MOOC. We can't estimate a risk or rate directly from a case control study Because we or the researchers, decide on the number disease people, the cases. Instead We estimate the risk ratio or the rate ratio in a case control study using the odds ratio.

This course explores public health issues like cardiovascular and infectious diseases – both locally and globally – through the lens of epidemiology.[MUSIC] Welcome, in this segment we will discuss the odds ratio.

In this segment, you will learn how to define, calculate and interpret the odds ratio.

Rural areas with little access to regular health care. A total of 25 cases and 19 controls were identified.

Data obtained from the cases and controls found that 15 cases and 12 controls had received the vaccine.There are different ways that you can interpret a measure of association and words as illustrated here.You could say ,those in a traffic ac, accident were 1.62 times as likely to have been texting while driving compared with those who were not in a traffic accident in the past year.Or those in a traffic accident were 62% more likely to have been texting while driving.Then those who were not in a traffic accident in the past year.Lets look at an example of calculating and interpreting the odds ratio, using childhood vaccines and human papillomavirus.Researchers conducted a case control study to examine whether childhood vaccines Protected children against HPV in real world conditions i.e.And then we see there were 22 cases in 89 controls who did not consume scallops. Cases were 19.6 times as likely, compared to controls to have eaten the scallops.So to calculate the odds ration, you take the cross product, which is 218 times 89, divided by 45 times 22. In a case-control study, we calculate the exposure odds ratio.The odds ratio approximates the incident rate ratio or risk ratio under certain conditions. The probability of an event occurring divided by the probability of it not occurring. And when the odds ratio is less than one, there is a negative association. Cross, the cross product formula only works if the table is set up correctly.

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