About the Authors

Merel M. Tielemans

M.Tielemans@MDL.umcn.nl

Affiliations Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, the Netherlands, Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, the Netherlands

Jeroen Jaspers Focks

Affiliation Department of Cardiology, Radboud University Medical Center, Nijmegen, the Netherlands

Leo G. M. van Rossum

Affiliation Department of Epidemiology, Biostatistics and Health Technology Assessment, Radboud University Medical Center, Nijmegen, the Netherlands

Ties Eikendal

Affiliation Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, the Netherlands

Jan B. M. J. Jansen

Affiliations Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, the Netherlands, Department of Gastroenterology and Hepatology, Elkerliek Hospital, Helmond, the Netherlands

Robert J. F. Laheij

Affiliation Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, the Netherlands

Martijn G. H. van Oijen

Affiliations Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, the Netherlands, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America

Competing Interests

The authors have read the journal's policy and have the following conflicts: None of the authors are employes by Nycomed BV. Martijn G. H. van Oijen received unrestricted research grants from AstraZeneca, Nycomed BV, Janssen and Shire. He received consulting fees from Pfizer and AstraZeneca BV. Other authors do not have conflicts of interest. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Performed the experiments: MMT JJF. Analyzed the data: MMT JJF MGHvO. Designed the questionnaire: MGHvO LGMvR RJFL JBMJJ. Tested the questionnaire in a previous pilot study: TE MGHvO LGMvR RJFL JBMJJ. Collected data of the present study: TE. Prepared the first draft of the manuscript: MMT MGHvO. Participated sufficiently in the adaptation of the first version of the manuscript and approved submission of the current manuscript: MMT JJF LGMvR TE JBMJJ RJFL MGHvO. Performed database management: LGMvR.