[Benefits of low-threshold services for drug addicts exemplified by the city of Zurich]. 
Low threshold services for drug users are a comparatively new approach in programs for drug users.  The authors evaluate the facilities offered in Zurich with special regard to their establishment, concepts and objectives.  The change of paradigms from unconditional abstinence towards an accepting attitude is characterized and explained by the notions of conceptualization, differentiation and resubjectivation.  The evaluation aims at the assessment of these premises of low threshold programs for drug users.  The assessment is scheduled in three stages from January to December 1995.  This requires the use of standardized quantitative and guideline based qualitative instruments.  In baseline interviews a total of 837 contacts with 655 persons could be achieved.  Sociodemographic features, drug career and frequency of use of the different facilities on the sample day are described as initial data.  A recontact rate of 60% from the first panel of interviews which ended in January 1995 considered satisfactory.