Relative risk ratio

In clinical epidemiology and evidence-based medicine, the relative risk or relative risk ratio, is a measure of the likelihood of a clinical outcome in group of patients exposed to a factor compared to a control group of patients. This measure should be contrasted with the absolute risk reduction.

Calculations

 * $$\mbox{Experimental event rate EER)} =\left (\frac{\mbox{ Cell A}}{\mbox{Total in the }experimental\mbox{ group}}\right )$$


 * $$\mbox{Control event rate (CER)} =\left (\frac{\mbox{Cell C}}{\mbox{Total in the }control\mbox{ group}}\right)$$


 * $$\mbox{Relative risk} =\left (\frac{\mbox{EER}}{\mbox{CER}}\right)$$

Note that the relative risk ratio is that same as 1 - the relative risk reduction.