[1] Free Univ Berlin, Charite Sch Med, Inst Occupat Med, D-14195 Berlin, Germany
[2] Humboldt Univ, D-14195 Berlin, Germany
[3] Hannover Med Sch, Dept Resp Med, D-30625 Hannover, Germany
[4] Hlth Care Campus North Rhine Westphalia, Strategy Ctr Hlth, D-44799 Bochum, Germany
[5] Univ Hosp Gottingen, Dept Cardiol & Pneumol, Gottingen, Germany