The absolute difference in rates of good or harmful outcomes between experimental groups (experimental group risk, or EGR) and control groups (control group risk, or CGR), calculated as the risk in the control group minus the risk in the experimental group (CGR – EGR). For instance, if the rate of adverse events is 20% in the control group and 10% in the treatment group, the absolute difference is 20% – 10% = 10%.