Funding for this research was provided by:
U.S. Department of Veterans Affairs (#2011-0521)
Received: 18 July 2018
Accepted: 26 July 2019
First Online: 19 August 2019
Ethics approval and consent to participate
: The study was reviewed by the Human Subject Protection Committee (HSPC) of the RAND Corporation and determined to be exempt.
: Not applicable.
: The authors declare that they have no competing interests.