Aggressive behaviour in mentally altered patients in prehospital setting as a threat to emergency medical service personnel: potential predictors identification.

Objectives: Patients are the most common source of violence against EMS personnel. This study aims at elucidating specific clinical features in patients with mental alteration and aggressive behaviour increasing risk of violence.

Material and methods: This consecutive cross-sectional retrospective study analysed consecutive patients treated for prespecified list of primary diagnoses by one EMS provider in the Czech Republic between 1 January 2021 and 31 December 2023. The effect of individual features of medical history and present symptoms on the occurrence of violence, need for the Police assistance and use of restraints was evaluated, using linear regression model.

Results: 410 patients were evaluated. Verbal and brachial violence was present in 21.5 and 12.9 %, respectively. Police assistance was needed in 48.3 %, restraints were used in 4.6 %. The most significant predictor for violence, need for Police or restraints was agitation (OR 7.02, CI 4.14 - 11.90; OR 2.60, CI 1.60 - 4.24, OR 11.02, CI 3.49 - 34.80 respectively). Other predictors of violence included history of acute psychotic attacks and psychotic disorders, or outpatient psychiatry care. Among other predictors for Police assistance was presence of delusions, paranoia and history of outpatient psychiatry care.

Conclusion: Prehospital care for patients with mental status alteration and aggressive behaviour is complex. Some clinical features seem to increase the risk of violence. Future research in the evaluation of agitated and violent patients is warranted to find strategies of risk mitigation for EMS personnel.