Estimated trends in the prevalence of heroin addiction in Switzerland. A multiple-indicator approach.

Data on the prevalence of heroin addiction have considerable relevance in the field of public health as a means of evaluating measures aimed at improving the lives of the individuals concerned. The number of heroin addicts in Switzerland was estimated by six different methods based on various data sources. This resulted in an overall estimate for the reference year 1997 ranging from a minimum of 24,000 to a maximum of 35,000 heroin addicts. In the 1990s, the trend in the prevalence of heroin addiction was characterised by a rapid rise up to 1993/94 followed by a gradual decline. The increasing medicalisation (focus on treatment rather than on punishment) of Switzerland's heroin problem has therefore not translated into a clear downward trend in the estimated prevalence of heroin addiction; however, the data for the various sub-groups lend plausibility to the assumption that this population is more integrated, less conspicuous and receiving better medical care.