Funding for this research was provided by:
Robert Wood Johnson Foundation (72695)
Received: 25 February 2019
Accepted: 31 July 2019
First Online: 8 August 2019
Ethics approval and consent to participate
: This study was approved by the University of Pennsylvania’s Institutional Review Board (#827652). A written consent was obtained from the participants.
: Not applicable.
: The authors declare that they have no competing interests.