[1] Oxford Univ Hosp NHS Fdn Trust, Dept Clin & Lab Immunol, Oxford, England
[2] Univ Oxford, Churchill Hosp Campus, Oxford Ctr Resp Med, Oxford, England
[3] Univ Oxford, Churchill Hosp Campus, NIHR Oxford Biomed Res Ctr, Oxford, England
[4] Churchill Hosp, Oxford Ctr Resp Med, Sleep Unit, Oxford OX3 7LJ, England
[5] Univ Zurich, Ctr Interdisciplinary Sleep Res, Zurich, Switzerland
[6] Univ Zurich Hosp, Sleep Disorders Ctr, CH-8091 Zurich, Switzerland
[7] Univ Zurich Hosp, Div Pulm, CH-8091 Zurich, Switzerland