Age and gender as independent predictors of violence under the influence of alcohol in Zurich, Switzerland.

Violent behaviour associated with alcohol consumption is frequently reported by different media. Clinical data analysing the correlation between alcohol intoxication, age, gender and violence are scarce. The aim of this study was to evaluate the influence of age, gender and blood alcohol content on violent behaviour under the influence of alcohol under central European conditions. Three hundred patients admitted to the emergency department were included into this study in the time period from January 01. to December 31. 2009. The inclusion criteria were a blood alcohol content (BAC) of ≥10 mmol/l, any traumatic injury and an age ≥16 years. Violence was defined as an evitable act committed by others leading to patient's hospitalisation. The data were compared with Wilcoxon and χ2-test for proportions. The data were considered as significant if p<0,05. Predictive quality was evaluated by using receiver operating characteristic (ROC) curve. Independent predictors were analyzed by logistic regression analysis. The average age was 36,9±16,9 years (range: 16-84 years), 259 (86%) males and 41 (24%) females. There was a significant difference in gender (odds ratio for gender male 2,88; CI 95%: 1,24-6,67; p<0,001) and age dependent (odds ratio for each year of age 0,94; CI 95%: 0,93-0,96; p<0,0001) violence with no correlation to blood alcohol content found. Logistic regression analysis revealed male gender and young age as an independent predictor for violence. These results clarify the relationship between alcohol, age, gender and violence and have important implications for municipal-level alcohol policies.