Funding for this research was provided by:
National Heart, Lung, and Blood Institute (R01HL126694, K24HL133444)
Agency for Healthcare Research and Quality (K08HS025455)
Received: 13 December 2018
Accepted: 24 March 2019
First Online: 11 April 2019
Ethics approval and consent to participate
: This study was reviewed by the University of Pittsburgh Human Research Protections Office and was determined to be exempt from human subjects review under Exemption 4 of the United States Code of Federal Regulations in that it used only existing, publicly available data and the subjects cannot be identified (Reference # PRO11100193).
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.