Risk assessment: predicting violence

Violence in its many and varied forms represents a major public health problem. Home Office figures for England & Wales, based on the British Crime Survey, suggest that there were just over two million incidents of violence between January and December 2010.1 It is therefore not surprising that significant efforts have been made to predict the risk of future violence in at risk groups. At a fundamental level, the challenges of assessing risk in this area are similar to those in other areas of public health, where uncertainty can be divided into two types: aleatory and epistemological. Aleatory uncertainty refers to what might also be termed true chance or randomness, as in the throw of a dice, the toss of a coin or the similar types of events which fill statistics textbooks. Epistemological uncertainty refers to our lack of knowledge about potentially verifiable events. In areas such…