Article History
Received: 22 November 2018
Revised: 9 February 2019
Accepted: 8 March 2019
First Online: 22 March 2019
Compliance with ethical standards
:
: The scientific guarantor of this publication is B. Keegan Markhardt, M.D. (corresponding author).
: The authors declare that they have no conflict of interest.
: One of the authors has significant statistical expertise and has a degree in statistics.
: Written informed consent was waived by the Institutional Review Board.
: Institutional Review Board approval was obtained.
: • retrospective• case–control study• performed at one institution