Relative Risk with 95% Confidence Intervals

The following is a 2 by 2 webulator used to compute relative risk . Enter the data in the cells for the appropriate rows and columns (the green coloured cells), then click on the button labelled Compute to compute the relative risk .

 +ve condition (CASES) -ve condition (CONTROLS) Numerator (a/(a+b)) Exposed +ve condition (CASES) -ve condition (CONTROLS) Denominator (c/(c+d)) Not Exposed Column Totals = Relative Risk = (a/(a+b)) / (c/(c+d)) ln Relative Risk

 Standard Error of lnRR 95%CI lnRR lower limit 95%CI lnRR upper limit Exponentiating the 95% Confidence Interval's Upper and Lower limits will return the estimated values to the original scale scores lower limit of 95%CIRelative Risk upper limit of 95%CIRelative Risk

The relative risk estimate suggests that:
The condition (or outcome) is RR times more likely to occur among those individuals that are exposed to the suspected risk factor (related to) THAN among those individuals with no exposure to the risk factor (unrelated to).

As a rule, the larger the value of the relative risk, that is greater than 1, the stronger the association between the disease or disorder of interest and exposure to the risk factor.

Likewise, values of the relative risk estimate that are close to 1 indicate that the disease and exposure to the risk factor are unrelated (i.e., the risk of occurrence is the same for both exposed and non-exposed individuals).

Similarly values of RR less than 1 indicate a negative association between the risk factor and the disease. A relative risk estimate less than 1 is said to demonstrate a protective effect rather than a detrimental effect.