Milea Timbergen

238 Acknowledgements The authors would like to thank the participants of the focus groups for their cooperation and input. We would also like to thank the researchers who assisted during the focus group sessions. Finally, we would like to thank Wichor Matthijs Bramer, BSc, from the Medical Library, Erasmus MC - University Medical Centre Rotterdam, the Netherlands, for his assistance with the systematic literature search. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Approval from the Medical Ethics Committee of Erasmus MC in Rotterdam, the Netherlands was obtained for this study (file number MEC-2017-269). Informed consent Informed consent was obtained from all individual participants included in the study. Funding This study was funded by the Stichting Coolsingel, Rotterdam, the Netherlands, grant number 566. 8