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.
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.
Often called “the cornerstone” of public health, epidemiology is the study of the distribution and determinants of diseases, health conditions, or events among populations and the application of that study to control health problems.
By applying the concepts learned in this course to current public health problems and issues, students will understand the practice of epidemiology as it relates to real life and makes for a better appreciation of public health programs and policies.
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.
You conduct a case control study to identify food associated with the illness.
A total of 240 cases and 134 controls were identified.