Text and Data Mining valid from 2019-11-27
Received: 21 June 2019
Revised: 30 July 2019
Accepted: 18 September 2019
First Online: 27 November 2019
Compliance with ethical standards
: The scientific guarantor of this publication is Qing-Song Xu.
: The authors declare that they have no conflict of interest.
: No complex statistical methods were necessary for this paper.
: Written informed consent was obtained from all patients in this study.
: Institutional Review Board approval was obtained.
: • prospective• randomized controlled trial• performed at one institution