1. Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
2. Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
3. Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
4. Department of Neurology, Erasmus Medical Center, Rotterdam, The Netherlands
5. Department of Respiratory Medicine, Erasmus Medical Center, Rotterdam, The Netherlands