- Correspondence to Dr Yawei Zhang, Section of Surgical Outcomes and Epidemiology, Department of Surgery, Yale School of Medicine, Yale School of Public Health, Yale Cancer Center, 60 College Street, LEPH 440, New Haven, CT 06520, USA;
- Received June 27, 2016
- Revised January 5, 2017
- Accepted January 18, 2017
- First published February 15, 2017.
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