Received: 29 May 2018
Accepted: 2 January 2019
First Online: 8 January 2019
Ethics approval and consent to participate
: The ethics review committee of the Wum District Hospital approved this study, and the director of the Wum District Hospital granted authorization prior to commencing the study. As this was a retrospective review of medical records, no participant informed consent was required.
: Not applicable.
: The authors declare they have no competing interests.
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