Funding/ Acknowledgements

No particular funding was obtained for the purpose of this study. MN is supported by a research grant of the Swiss National Science Foundation (#179334). AE received grant support from the Research Fund of the Swiss Lung Association, Bern and the Uniscientia foundation. The study was supported by a research grant of Bühlmann Laboratories (test kits). We thank Daniela Sturny, Christof Schild, Barbara Pula, Juliette Schlatter, Raphael Bratschi, Monika Hurni, Thomas Momot, Vincent Benites, Karin Volken, Margret Bachmann, Dominique Rowedder, Karin Balmer and Michelle Rickli for the great support. All authors, external and internal, had full access to all of the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.