Absolute Risk Reduction

In clinical trials, in order to understand the results of the trial we need to compare the risk of bad outcomes in patients receiving the intervention and those receiving the control. The most common methods used in expressing information about treatment options and risk reductions are absolute risk, absolute risk reduction, relative risk and relative risk reduction. Absolute risk reduction (ARR) or Risk difference (RD) is the most practical and useful method to interpret research results and is most important in clinical decision making. However, the relative risk and relative risk reduction is more commonly used among studies .1,2
Definitions
Absolute risk (AR) is defined as the term used to indicate that a certain event (outcome) will actually happen or the incidence of developing the outcome among population and is calculated as the number of patients developing …show more content…
Calculating absolute risk indicates the probability of the outcome on population in percentage when using the intervention or control. Absolute risk reduction indicates the difference of risk when using the intervention and control within the population helping in decision making.5
In clinical trials, several concerns have recently appeared regarding reporting results in terms of relative values rather than absolute ones. These concerns include misinterpreting the extent of effect of certain intervention. Reporting relative risk values in studies where the intervention appears to have a larger effect than the actual one is more controversial. 6 In order for the relative risk values among studies to be statistically significant, a confidence interval of 95% must be reported and it can't include 1. However, no matter how well calculated the relative and absolute risk; we need put the quality of the study design, confounders and biases into consideration before validating the results of the