1. Department of Medical Statistics; University Medical Center Göttingen; Humboldtallee 32 37073 Göttingen Germany
2. Lungenfachklinik Immenhausen; Robert-Koch-Straße 3 34376 Immenhausen Germany
3. Clinics for Cardiology and Pulmonology; University Medical Center Göttingen; Robert-Koch-Straße 40 37099 Göttingen Germany