[1] Otto Wagner Hosp, Dept Resp & Crit Care Med 1, Vienna, Austria
[2] Otto Wagner Hosp, Ludwig Boltzmann Inst COPD & Resp Epidemiol, Vienna, Austria
[3] Otto Wagner Hosp, Dept Resp & Crit Care Med 2, Vienna, Austria
[4] Sigmund Freud Univ, Med Sch, Vienna, Austria
[5] Otto Wagner Spital, Ludwig Boltzmann Inst COPD & Resp Epidemiol, Vienna, Austria