Background: Germany provides a wide range of highly developed mental health care to its citizens. The aim of this study was to identify factors influencing the voluntariness of admissions to psychiatric hospitals. Especially the impact of demographic factors of the region, characteristics of the psychiatric hospitals and characteristics of the psychosocial services was analyzed.

Method: A retrospective analysis of hospital admission registers from 13 German adult psychiatric hospitals in 2009 was conducted. Public data on the regional psychiatric accommodation and demographic situation were added. Hospitals were dichotomously divided according to their index of involuntary admissions. Group comparisons were performed between the clinics with low and high involuntary admission indices. Analysis was conducted with clinical, psychiatric provision and demographic data related to inpatients in the Landschaftsverbands Westfalen-Lippe (LWL)-PsychiatryNetwork.

Results: Especially the range of services provided by the social-psychiatric services in the region such as number of supervised patients and home visits had an influence on the proportion of involuntary admissions to a psychiatric hospital. Some demographic characteristics of the region such as discretionary income showed further influence. Contrary to our expectations, the characteristics of the individual hospital seem to have no influence on the admission rate.

Conclusion: Social-psychiatric services show a preventive impact on involuntary acute psychiatry interventions. Sociodemographic factors and patient variables play a role with regard to the number of involuntary hospitalizations, whereas characteristics of hospitals seemed to play no role.