Accepted: 9 July 2018
First Online: 9 August 2018
Compliance with Ethical Standards
: The views expressed in this article are those of the authors and do not necessarily reflect the official policies of the U.S. Department of Health and Human Services or the Health Resources and Services Administration, nor does mention of the department or agency names imply endorsement by the U.S. government.
: The authors have indicated they have no potential conflicts of interest to disclose.