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Article History

Received: 30 October 2017

Accepted: 22 May 2018

First Online: 11 June 2018

Ethics approval and consent to participate

: Ethics approval was not applicable. This was a research-on-research study of pre-existing published research; therefore, there was no patient recruitment.

: The authors declare that they have no competing interests. All authors have completed the International Committee of Medical Journal Editors uniform disclosure form at (available on request from the corresponding author) and declare that they received no support from any organization for the submitted work, they have no financial relationships with any organizations that might have an interest in the submitted work in the previous 3 years, and they have no other relationships or activities that could appear to have influenced the submitted work.

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