Patient violence in a psychiatric hospital in Denmark - Rate of violence and relation to diagnosis

In a 1-year prospective study inpatient violence was investigated in a Danish psychiatric hospital covering a well-defined catchment area with a population of 235,000. Violent acts were recorded on the Staff Observation Aggression Scale. Psychiatric diagnoses were recorded as ICD-8. Six per cent of the inpatients behaved violently. The total rate of violent acts was 1.40 per bed (occupied) per year. For more serious violence it was 0.35. Ninety-three per cent of the violent patients had major (psychotic) mental disorders. Comparisons of violent with nonviolent psychotic patients showed that for both sexes schizophrenia, paranoid type, was strongly associated with violence. Mania was also connected with violence, but significantly only in females. Half of the violent patients had the double diagnoses psychosis plus abuse of alcohol or drugs. The most frequent victims of violence were nursing staff. Most injuries were trivial. The most frequent provoking factors were demands on patients and/or the staff's refusal to comply with patient wishes. Coercion was frequently used on patients with psychotic mental disorders. There was a strong association between the use of coercive measures and violent behaviour.