The process of subtracting the risk of an event in one group from the risk of the same event in another group yields a valuable metric in assessing the impact of interventions or exposures. For example, if 10% of individuals receiving a placebo experience a specific adverse effect, while only 5% of individuals receiving a treatment experience the same effect, this value is determined by subtracting the latter percentage from the former. The resultant value of 5% represents the additional effect prevented by the treatment in the population under study.
This straightforward measure allows for a clear understanding of the tangible effect of a treatment or exposure. It’s particularly useful for communicating risk information to patients, policymakers, and the public, because it expresses the benefit or harm in absolute terms. This method provides a more meaningful interpretation of results than relative risk measures alone and has become increasingly important in evidence-based decision making across numerous fields, allowing for straightforward comparisons between different treatments or interventions to determine which is most effective in reducing a specific risk. It also plays a significant role in public health, informing strategies for disease prevention and control.
