Funding for this research was provided by:
Instituto de Salud Carlos III (PI15CIII/00047)
Received: 16 November 2020
Accepted: 12 April 2021
First Online: 23 April 2021
: This study was approved by the Ethics Committee of the Spanish Carlos III National Health Institute (CEI PI 50_2016). Interviewees gave written informed consent to take part in the study.
: Not applicable.
: The authors declare that they have no competing interests.