Funding for this research was provided by:
Text and Data Mining valid from 2018-08-29
Received: 14 December 2017
Accepted: 13 August 2018
First Online: 29 August 2018
Ethics approval and consent to participate
: IRB approval was not obtained because this study was an analysis of de-identified secondary data [ CitationRef removed ].
: Not applicable.
: Conflict of interest statement: Drs. Yang and Petigara are employees of Merck & Co., Inc., Kenilworth, NJ, USA,.Dr. Zhang was a Merck & Co., Inc., Kenilworth, NJ, USA, employee when the study was conducted.
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