The Domestic Abuse, Stalking and Harassment and Honour-Based Violence (DASH) Risk Assessment Instrument in Predicting Deadly or Persistent Domestic Abuse

Background: The DASH risk assessment scheme is used across the UK to identify and manage instances of domestic abuse. Recent studies have questioned whether the scheme can identify offenders who go on to commit further acts of domestic abuse, in particular serious violence, and therefore whether it is fit for purpose. Methods: We therefore tested the ability of the DASH to predict future instances of deadly or persistent domestic abuse. From a database of ≈25,000 incidents, we compared DASH assessments which preceded an incident of “deadly violence” or was the first in a series of “persistent abuse”. These groups were compared to a control group where there was no further incident of domestic abuse. Results: The proportion of “high-risk” stratifications was approximately 5 times higher in the deadly violence group compared to the control group. Prediction accuracy assessed via signal detection theory showed the DASH was a moderate predictor of deadly violence (AUC = 0.67). The DASH also showed predictive accuracy in identifying persistent offenders (AUC = 0.62). While these results are encouraging and are similar in efficacy to other risk assessment schemes used in the prediction of domestic violence, the results identified that many individual items of the DASH were not predictive. The inclusion of non-predictive items within the DASH adds “noise” and error into the risk evaluation. The development of a shortened version of the DASH, removing these ineffectual items, was shown to have even higher predictive value for deadly violence (AUC = 0.80). Conclusions: We stress, however, that the role of risk assessment is not to predict violence per se, but to prevent violence via the accurate identification of dangerous perpetrators and via effective intervention and safeguarding of victims. Despite this, research such as this is imperative to evaluate if the risk assessment schemes selected by practitioners and police are fit for purpose.