Funding for this research was provided by:
EuroQol Research Foundation (2015200)
Received: 12 November 2020
Accepted: 24 February 2021
First Online: 6 March 2021
: The research study was approved by the Ethics Committee of Bielefeld University, Number 2017-207. This study was conducted on secondary, anonymized date that were previously collected. Informed consent for study participation was obtained from all individual participants included in the study.
: All authors have agreed to publish this study.
: OM and WG are members of the EuroQol Group. There are no other competing interests.