About the Authors

Judy M. Bradley

Affiliation Institute of Nursing and Health Research, University of Ulster, Ulster, Northern Ireland

Paul Koker

Affiliation Boehringer Ingelheim Pharmaceuticals Inc, Ridgefield, Connecticut, United States of America

Qiqi Deng

Affiliation Boehringer Ingelheim Pharmaceuticals Inc, Ridgefield, Connecticut, United States of America

Petra Moroni-Zentgraf

Affiliation Boehringer Ingelheim Pharma GmbH & Co KG, Ingelheim, Germany

Felix Ratjen

Affiliation The Hospital for Sick Children, Toronto, Ontario, Canada

David E. Geller

Affiliation Florida State University College of Medicine, Orlando, Florida, United States of America

J. Stuart Elborn

s.elborn@qub.ac.uk

Affiliation Centre for Infection and Immunity, Queen’s University Belfast, Belfast, Northern Ireland

on behalf of the Tiotropium Cystic Fibrosis Study Group

Competing Interests

The authors have read the journal’s policy, declare the following conflicts of interest, and confirm that these do not alter their adherence to PLOS ONE policies on sharing data and materials: JSE acted as a consultant for Boehringer Ingelheim and was principal investigator for this study; JMB declares no conflicts; PK, QD, and PMZ are employees of Boehringer Ingelheim; FR acts as a consultant for Boehringer Ingelheim and is the principal investigator for the phase 3 study of tiotropium in CF; DEG declares no conflicts related to bronchodilators in CF.

Author Contributions

Performed the experiments: JB PK QD PMZ FR DG JSE. Analyzed the data: JB PK QD PMZ FR DG JSE. Wrote the paper: JB PK QD PMZ FR DG JSE. Contributed to the planning and design of the trial: JB PK QD PMZ FR DG JSE.