The completeness of routine registration of the counterpart in deliberate interpersonal violence in an urban emergency department.

Most studies of violence from the health care system lack reliable information about the counterpart, which is important for distinguishing between different types of violence. Since 2014, the emergency department at Odense University Hospital in Denmark has routinely registered information about the counterpart. The purpose of this study was to evaluate the completeness of registering information about the counterpart during routine registration of victims of interpersonal violence in the emergency department. We included 11,200 victims treated at the emergency department 2014-2021. Using the patient registration data, we estimated the proportion of missing information on the counterpart, stratified by age group and gender of the victim as well as type of incident and severity of injury. Information about the counterpart was registered in 91.5 % of all cases. In 43.1 % (CI: 42.2-44.0) of the cases, the counterpart was unknown to the victim, in 24.3 % (CI: 23.5-25.1) the counterpart was an acquaintance, in 10.5 % (CI: 10.0-11.1) the counterpart was a partner, and in 4.2 % (CI: 3.8-4.5) the counterpart was another family member. The proportion of cases with no information about the counterpart varied with gender, age group, time of violence, place of violence, weapon use, and severity of injury. Half of the victims injured with firearms (46.2 %, CI: 30.1-62.8) and one-fourth of the victims injured with knives (25.9 %, CI: 21.9-30.2) did not reveal information about the counterpart. The majority of the victims revealed information about the counterpart, making it possible to analyse different types of violence separately.