1 Department of Medicine, Blekinge Hospital, Karlskrona SE-37185, Sweden; Respiratory Medicine, Allergology and Palliative Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden. Electronic address: magnus.ekstrom@med.lu.se.
2 Obstructive Lung Disease in Northern Sweden (OLIN) Unit, Section of Sustainable Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
3 Department of Medicine, University of Kentucky College of Medicine, Lexington, KY, USA; COPD Foundation, Washington, DC, USA.