Received: 29 May 2017
Accepted: 2 March 2018
First Online: 9 March 2018
Ethics approval and consent to participate
: The Colorado Multiple Institutional Review Board, the Institutional Review Board for the CUSOM, approved this study. Informed consent was not required as the study analyzed only pre-existing de-identified data.
: Not applicable.
: The authors declare that they have no competing interests.
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