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.

## Comments Case Control Study Odds Ratio Interpretation

## Explaining Odds Ratios - nih.gov

The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well with some modifications and/or assumptions.…

## On the use, misuse and interpretation of odds ratios. The BMJ

On the use, misuse and interpretation of odds ratios. Therefore, the ratio of the odds of exposure among cases to the odds of exposure among non-cases is calculated. In theory, all case-control studies can be viewed as nested case-control studies, in which both cases and controls are drawn from a well defined source population.…

## How does one correctly interpret odds ratio from case-

Because case-control studies by definition begin with the outcome and then investigate the presence or absence of an exposure, I would report the OR in terms of the exposure. The odds ratio addresses the exposure since you already know - in both groups - whether or not the outcome is present it's.…

## Measuring Association in Case-Control Studies

Incidence is Unknown in a Case-Control Study. In a cohort type study, one can calculate the incidence in each group, the risk ratio, the risk difference, and the attributable fraction. In addition, one can also calculate an odds ratio in a cohort study, as we did in the two examples immediately above.…

## Interpreting Results of Case-Control Studies - cdc.gov

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 no t have the exposure.…

## What is an Odds Ratio and How do I Interpret It? - Critical Appraisal

Odds Ratio OR is a measure of association between exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Important points about Odds ratio Calculated in case-control studies as incidence of outcome is not known…

## How does one correctly interpret odds ratio from case-control studies?

All Answers 28 If the sampling fraction for both cases and controls is known then you will be able to calculate the risk ratio. If your case-control study is nested within a well defined cohort, the odds ratio will be a good approximation of the risk ratio if the sampling is done using the case-base method.…

## Case-Control Studies Odds Ratios - sjsu.edu

Pairs in which the control but not the case reported low fruit/veggie consumption.3 Based on this information, the odds ratio estimate 24 45 = = v u ˆOR = 1.88, indicating that low fruit/veggie “exposure” was associated with an 88% increase in risk. The 95% confidence interval for the odd ratio parameter is calculated. The lnOR^ = 0.6286 and 24 1 45…

## Odds Ratio - Measures of Association Coursera

The odds ratio is the ratio of the odds of the health outcome or disease in the exposed Relative to the odds of the disease or health outcome in the none exposed or less exposed group. Odds ratios can be calculated in cohorts studies and in case control studies.…