[Work based on data of the Gmünder Ersatzkasse. An exemplary overview]

Since the 1990s, administrative data sources of statutory health insurance companies in Germany have significantly expanded. However, general statements with regard to data availability are not possible. Taking the example of the Gmünder Ersatzkasse (GEK) with currently about 1.6 million insured persons, this article will give an impression, which data, and since when, could have been used for scientific analysis. Examples of different topics (unemployment, alcohol abuse, outpatient psychotherapy, coronary revascularization) are given. Data exist on almost all sectors of health insurance coverage since the availability of information on outpatient care in the year 2004. Research opportunities - and hence the scientific value of these data - are mainly resulting from the acquisition of data at the personlevel. Only with person-level data can longitudinal and trans-sectoral analysis capabilities with clearly defined denominator populations arise. Due to the availability of data for large populations, previously nonexisting analysis options are now available.