[Compulsory admission of psychiatric patients in a national and international comparison--incidence and factors of influence].

The frequency of compulsory admissions of psychiatric patients is very variable if compared nationally and internationally. In the old Laender of West Germany, between 2.8% (Bremen) and 44.8% (West Berlin) of all psychiatric admissions were compulsory. The range is even broader, if one compares different western countries: while in Denmark the frequency of compulsory admissions is about 5% of all admissions, it is 50-93% in Switzerland. In this paper the reasons for this wide variation are analysed, making a distinction between "true" and "artificial" differences in frequency. Artificial differences are mainly due to insufficient representativity and comparability of the populations studied. True differences on the other hand are mainly a consequence of the differing legislation in the individual countries and of regional differences in administrative regulations, but also of the situation of mental health care. Apart from analysing these patient-independent factors influencing compulsory admission, the characteristics of patients are studied which are associated with a higher risk of compulsory admission. The relation of these patient characteristics with the factors "danger to oneself or others", which are the prerequisites of compulsory admission in most countries, is discussed.