Identify the exposed group and the unexposed group
Calculate the risk in the exposed group: number of events in exposed group divided by total exposed group
Calculate the risk in the unexposed group: number of events in unexposed group divided by total unexposed group
Divide the risk in the exposed group by the risk in the unexposed group
Use the formula: Risk Ratio = [a / (a + b)] ÷ [c / (c + d)]
Where a = events in exposed group, b = non-events in exposed group, c = events in unexposed group, d = non-events in unexposed group
Interpret the result as the relative risk of the event in the exposed group compared with the unexposed group