Absolute risk increase (ARI) is the absolute risk of adverse events in the exposed or treatment group (ART) minus the absolute risk of events in the control group (ARC): ARI = ART–ARC. This is also known as risk difference, as well as the proportion of treated persons who experience an adverse event minus the proportion of untreated persons who experience the event.

How can absolute risk increase (ARI) be calculated?

Absolute risk increase (ARI) can be calculated by subtracting the absolute risk of events in the control group (ARC) from the absolute risk of adverse events in the exposed or treatment group (ART): ARI = ART–ARC.

What is the difference between absolute risk increase (ARI) and risk difference?

Absolute risk increase (ARI) and risk difference are the same thing; they both refer to the absolute risk of adverse events in the exposed or treatment group (ART) minus the absolute risk of events in the control group (ARC): ARI = ART–ARC. Additionally, they both refer to the proportion of treated persons who experience an adverse event minus the proportion of untreated persons who experience the event.

Test your knowledge about absolute risk increase (ARI) and its calculation methods. Learn the differences between ARI and risk difference.