1. Department of Bioanalysis, Pharmaceutical Care Unit, Ghent University, Ottergemsesteenweg 460, 9000, Ghent, Belgium
2. Department of Epidemiology, Erasmus Medical Centre, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
3. Department of Otorhinolaryngology and Head and Neck Surgery, Erasmus Medical Centre, PO Box 2040, 3000 CA, Rotterdam, The Netherlands