Funding for this research was provided by:
Stockholms Läns Landsting (20100192; 20110608)
Received: 4 December 2017
Accepted: 14 October 2019
First Online: 30 October 2019
Ethics approval and consent to participate
: This study followed the ethical requirements stated in the Declaration of Helsinki. Written informed consent was obtained from the study participants. An advisory opinion from the Regional Research Ethics Committee in Stockholm was obtained, and as this study did not involve patients or relatives or sensitive personal information, no ethical approval was required under the Swedish Act concerning the Ethical Review of Research Involving Humans, from the Ministry of Education and Research [CitationRef removed].
: Not applicable.
: The authors declare that they have no competing interests.