[Epidemiologic studies among foreign immigrants in Germany--rational and obstacles].

About 7.2 million foreign nationals are living in Germany. Only few epidemiological studies have assessed their health status, unlike in other countries with large migrant populations. Hence, it is not known whether foreigners in Germany experience special health risks and whether there is a need for specific public health interventions. The size of the group (9% of the total population) and their increasing length of stay further emphasise the need for epidemiological research on migrants. In this article we describe the obstacles for such studies in Germany: difficulties in characterising the group of interest; problems of availability and accessibility of data sources; and aspects of data protection. Minor changes in mortality statistics and improved access to existing data sources within the limits of data protection would improve research opportunities.