Relative Risk Reduction (RRR)« Back to Glossary Index
Relative Risk Reduction
The proportional reduction in frequency of harmful outcomes between experimental and control participants. It is calculated by dividing the frequency of harmful outcome in the control group minus the frequency of harmful outcome in the experimental group by the frequency of harmful outcomes in the control group. Thus if the risk is 10% in the control group and 8% in the treatment group the RRR is 20%. Used with a beneficial exposure or intervention.