Epidemiology of schizophrenia and risk factors of schizophrenia-associated aggression from 2011 to 2015

Objective: To investigate the risk factors associated with aggression in patients with schizophrenia. Methods: Patient clinical, behavioural, and demographic information was collected and reported online to the Beijing Mental Health Information Management System by psychiatrists. We used chi-square tests to analyse information between 2011 and 2015 to determine the prevalence and incidence of schizophrenia and the rate of aggression. We used univariate and binary logistic regression to analyse risk factors of aggressive behaviours. Results: The prevalence and incidence of schizophrenia, and the proportion of cases displaying aggressive behaviour, increased considerably from 2011 to 2015. Risk of aggression was associated with non-adherence to medication (odds ratio [OR]: 2.92; 95% confidence intervals [CI]: 2.08-4.11), being unmarried (OR: 1.62; 95% CI: 1.03-2.55), having physical disease (OR: 3.26; 95% CI: 2.28-4.66), and higher positive symptom scores (OR: 2.01; 95% CI: 1.06-3.81). Physical disease was a risk factor associated with committing more than one type of aggression. Conclusion: We confirmed that demographic factors, treatment-related factors, and clinical symptoms were associated with aggression in patients with schizophrenia in Beijing. A focus on improving controllable factors, including medication adherence and physical health status, might help to prevent aggressive behaviour.