Funding for this research was provided by:
First Online: 25 September 2018
Compliance with ethical standards
: Competing interests—intellectual or financial—in the research detailed in the manuscript: Anna Wolters: none. Guido de Wert: none. Onno van Schayck has received unrestricted grants for research funding from Pfizer, Boehringer Ingelheim, and Nabi. Klasien Horstman: none.
: This is to confirm that the manuscript comprises original material that is not under review elsewhere and that the study on which this research is based has received ethical approval from the Netherlands Central Committee for Research involving Human Subjects (CCMO).