When the risks (or odds) in the two groups being compared are both small (say less than 20%) then the odds will approximate to the risks and the odds ratio will approximate to the relative risk.
Can you convert odds ratio to risk ratio?
The simplest way to ensure that the interpretation is correct is to first convert the odds into a risk. For example, when the odds are 1:10, or 0.1, one person will have the event for every 10 who do not, and, using the formula, the risk of the event is 0.1/(1+0.1) = 0.091.
Can you use odds ratio to estimate the risk ratio if this is a case-control study?
Key Concept: In a study that is designed and conducted as a case-control study, you cannot calculate incidence. Therefore, you cannot calculate risk ratio or risk difference. You can only calculate an odds ratio. However, in certain situations a case-control study is the only feasible study design.
Would you say that your odds ratio is an accurate approximation of the risk ratio?
As a result, risks, rates, risk ratios or rate ratios cannot be calculated from the typical case-control study. However, you can calculate an odds ratio and interpret it as an approximation of the risk ratio, particularly when the disease is uncommon in the population.
When an odds ratio is used to estimate the relative risk quizlet?
When can OR be used to estimate RR? The odds ratio always approximates the relative risk if the disease is frequent. In a cohort study of obesity and myocardial infarction, the odds ratio was calculated to be 4.5 while the relative risk was 2.5.
Can odds ratio and relative risk be the same?
When the outcome is rare (typically <10%), the value of OR is not too different from that of RR, and the two can be used interchangeably irrespective of whether the risk is lower [Table 3b] or higher [Table 3c] in the exposed group as compared to the unexposed.